Except saying that she’s vain because she fell in love with Ten instead of Nine is absolutely incorrect, because she fell in love with Nine first, and initially did not accept Ten because he was not Nine.
Putting aside the fact that Christopher Eccleston is quite attractive (he’s not “pretty," no, but have you seen his eyes? They’re the color of an arctic ocean; they’re beautiful), anyone with eyes can see that Rose fell in love with Nine first. She may not have realized it, she may have not been as open with her affections, but it was there. For example: