This is just my opinion. I don't mean to offend anyone with it, and I'm more than open to thoughts, comments, and suggestions.
1. Minnie Mouse: She does portray a princess, queen, duchess, lady, pretty much everything from time-to-time, but she's also like the Queen of ALL things Disney, so I don't think she needs to be a Disney Princess. And the Mickey stories aren't consistent with each other like DP ones. Each movie/TV series/special has its own plot, setting, and character development, so it'd be hard to place who exactly Minnie is. There's really no strict canon, and she already gets enough recognition.
2. Daisy Duck: Same reasons as Minnie.
3. Faline: By Bambi becoming Prince of the Forest, she has absolute full rights to being a princess, and her fawns at the end of the film would be, too. Still, she's a deer, not human. I kind of wish there was a sub-franchise for animal princesses, since there's a lot of them.
4. Alice: Even though Alice never does become a princess technically, she is one in "Kingdom Hearts". Perhaps this implies she did become the Princess of Wonderland. Who knows? Either way, she's one somehow, so she should be added.
5. Wendy Darling: No. She's not a princess by any means, and she doesn't even end up with Peter Pan (see "Return to Neverland").
6. Tinkerbell: This one is tough. No, she's not a princess in any shape or form, but she still was once part of the franchise, and I don't like characters being in and dropped. That's just me. Although, I feel like Queen Clarion and Queen Eewee (from Disney Fairies) should get some royal recognition. Not "princess" necessarily since their queens, but something.
7. Maid Marian: Is she considered a princess? I guess I don't really know. It's been forever since I watched "Robin Hood". Her uncle is the king, and as far as I know, he has no daughters, and his brother is evil, so she'd be the heiress, correct? Assuming she is a princess, I'd like her added alongside other animals. Like I mentioned before, an Animal Disney Princess franchise would be cool :)
8. Eilonwy: Yes, yes, yes, yes. Eilonwy was born a princess, and the only reason she's not in the lineup is because "The Black Cauldron" tanked in the box office. Regardless, she is undeniably a princess.
9. Nala: Well, technically she's the Queen of the Pride Lands, but she deserves some sort of royal recognition. Really, the princess would be her daughter, Kiara.
10. Nita: This one is so forgotten! She's not even on the Unofficial Princesses List on Disney Wiki. Perhaps it's because she doesn't show up until a sequel (one of the few sequels I like, too), but Ting-Ting, Su, and Mei didn't either, so I don't know what's up here. It kind of irritates me, frankly. Anyway, in "Brother Bear 2", she's the daughter of a Native American or Eskimo chief. That makes her the princess of the tribe, like Pocahontas is.
11. Esmeralda: As much as I like her, she isn't a princess. Although, neither is Mulan, and she's actually my favorite. Esmeralda could be seen as a hero, a princess of the people, like Mulan, so if all of the other real princesses were added, I wouldn't mind. She was part of the original lineup, anyway.
12. Megara: She does marry Hercules, son of Zues, king of the gods, so I see where people are coming from when they want her in the lineup. She would appear to be the highest-ranking of the princesses, being a goddess sort of, but that's the problem. Zues has other daughters and daughter-in-laws. Artemis, Athena, Aphrodite... They'd be on the same playing ground, if not higher being they were BORN there. Sorry, but I think goddesses and princesses should be kept separate. **Prepares for flames** XD
13. Jane Porter: By marrying Tarzan, King of the Jungle, she could technically be seen as the Queen of the Jungle, but that's not princess. Now, if they had a daughter... Anyhoo, I would be all for being recognized as a queen if the animal royalty was, too, because even though Jane and Tarzan are human, their "subjects" are apes. Not human. Still, I don't think she belongs in a lineup with princesses, especially human ones.
14. Kida: She starts the movie as a princess, but it ends with her as a queen. Therefore, she's not a princess anymore. I'm all for her being an official queen if there's such a thing, but not a princess.
15. Tiger Lily: I should've done her up with the "Peter Pan" girls. Oh, well. I guess she could be added because she is the daughter of a chief like Pocahontas (and Nita). She's not a major character, though, so she's not at the top of my list, but in an ideal world, sure.
16. Vanellope von Schweetz: Yes. She's just the princess of a videogame, but a princess nonetheless. She does become president later, but that could add diversity. A democratic princess? In America, that could take off maybe.
17. Dot: She's a princess in her own right, as her mother was once Queen, and now her older sister (Atta) is. If animals are ever included, Dot should be also.
18. Jessie: I don't really know why people consider her a princess. She has no royal ties whatsoever, and she's a toy. Animal princesses are cute. Toy princesses, I don't know, that's pushing it for me.
19. Sally: Nooooo. Big N. O. No royal ties at all, and that movie is fucking... err... kid site... frickin'... creepy.
20. Jessica Rabbit: Might as well get all the baddies in one swing. Granted, I've never seen "Who Framed Rodger Rabbit", but it looks stupid. I know, don't judge a book by it's cover, but this is a movie, so all arguments are invalid ^_^ From my extensive research (as in Wikipedia- I'm 16, that is extensive), she appears to have no royal ties and is just a scantily clad singer that married a rabbit. Gross. Illegal.
21. Giselle: The main argument against her is being live-action, but she was animated originally, and she references a lot of official DPs. However, she never did marry Edward, so she never did become a princess. It's sort of a relief, really, because I never did like her. Her personality grates me, and her romance is weird. She acts like a stereotypical Disney Princess in every way, which also means she's probably very young, a teenager. Robert has a 6-year-old daughter and is an experienced lawyer. How old is he?! Law school is 8 years, so he'd be at least 26, tack on a few years of experience to get his standing, and he's likely in his early 30's. Giselle could very easily be only 18, actually in the older section of the DPs. Da fuq? Yeah, my issues with "Enchanted". If anyone's a princess, it's Nancy, who did marry Robert, but I don't like her either.
22. Calla: Here's another forgotten princess. I only know about her because of Disney Wiki. I've never seen "The Adventures of the Gummi Bears". It could be adorable, or it could be really dumb, couldn't tell ya. Still, she's a born princess, so she should be recognized as such.
23. Sofia: Absolutely posilutely! Even though she's only 7, even younger than Alice, she's still a princess. The whole show is full of princesses. I get that the DPs are supposed to be role-models, therefore older, but little girls would be able to relate better to Sofia. Of course they can also relate to the older ones, but not as much since there's such an age difference. Sofia would be their age. She's still fairly new, though, so she at least has a shot, however small, of being added to the lineup. And she looks exactly like me when I was 7 :)
24. Melody: She's second generation, so I don't know if she counts since when the DPs are portrayed, it's as still teens, not adults, so there's that. I don't really have an opinion on her.
25. Ariel's Sisters: Aquata, Andrina, Artista, Attina, Adella, and Alana. They are princesses, but I get why they aren't marketed a lot. There's 6 of them. Geez Triton, get a hobby! Lol
26. Charlotte: She was the Princess of Mardi Grass, but that doesn't really count. She doesn't have a kingdom, and it was just for a day. And she's annoying!
27. Ting-Ting, Su, and Mei: I can't say I love "Mulan 2". It was so much better left alone, but they're princesses. If Mulan is a DP, then these birth princesses should be, too.
28. Kiari: To me, videogames do count. They're still animated, and this incorporated actual DPs, so Kiari, a birth princess, should be added to the lineup.
29. Kilala Reno: Being Disney didn't actually make this manga, it'd probably be hard to add her, but if they can, why not? Don't have an opinion here.
30. Elsa: "Frozen" hasn't been released yet, so I might change my mind. For now, it seems though that she's a queen of some sort, not a princess.
31. Malina: Come on, who hasn't thought of this one? She's not royalty, but Kuzco is, and they're totally going to get married. I guess that'd make her an empress, but whatever :P
32. Lilo: Why is she even considered? She's not a princess.
33. Katrina van Tassel: Not a princess, just treated like one.
34. Leia: This is hard because Disney does own the Star Wars franchise now, but they didn't when the movie was made, so there's still mental if not legal separation there. Besides, not many fans are little girls (or big girls!) like with DP.
35. Marie: This a character I just discovered off of Wikipedia. She is from "The Adventures of the Gummi Bears", the same show as Calla. There's also a prince from the "Far East" called Yen-Moon. I admittedly know nothing about either of them, but it sounds like Marie is a fairly large character, so why not?
Please leave your opinions, comments, suggestions, and ideas ♥