Disney's The Little Mermaid: Magic in Two Kingdoms
Disney Princess
Disney Princess Royal Adventure
My Little Pony Crystal Princess: The Runaway Rainbow
a multitude of different Barbie games
MegaDrive:
Ariel the Little Mermaid
(I played this one as a kid, but I don't remember much from it)
SNES:
Barbie Vacation Adventure
The Great Circus Mystery Starring Mickey and Minnie
Kirby Super Star
Kirby's Dream Land 3
The Wizard of Oz.
The Great Circus Mystery game was one of my favorites to play with my younger brother. It has an amazing 2 player mode where a second player can join at any time, which probably doesn't help in this case, but it's a great game to play together. Similar mechanics and style: The Magical Quest Starring Mickey Mouse. These 2 games (and the third game) are also on the GBA and listed above as Disney's Magical Quest 1, 2, and 3.
I've only personally played Ariel the Little Mermaid and Great Circus Mystery, all of the others I just now opened to get an idea of how they play to see if they're cute. If many of these don't fit the bill, I at least highly recommend the Magical Quest ones on either system. I hope this helps your search.