Prince, Paris, and Blankets height?

IMDB says Prince, Paris, and Blankets heights are

Prince: 5ft 7in
Paris: 5ft 5in
Blanket:4ft 7in

Last time I checked the site Prince was 5ft 1in at his fathers death that means he's grown half a foot thats a hell of alot height to gain in a year and a half and at the time of her fathers death it say Paris was 4ft 8in and I'm the same age as her and at the time of her fathers death I was also 4ft 8in and don't say its genetics cause my dad is 5ft 11in and so was Michael our mothers are 5ft 4in and so is my mom so we'd be the same height and Blanket is 2 months younger than my sister and is 5 inches taller than her and my sister has a disease that makes her taller than she should be so how in the hell could they be this tall? I don't think they are cause if they are Prince is 7 inches taller than me and Paris is 5 inches taller than me yet me and Paris look very close i height and weight in pictures and I even look taller than her sometimes so I really doubt they are this tall.