1.They both are funny.
2.They both have head asserories
3.They both wear shorts.
Snow White and Elsa(The first question)
1.They are both animals.1. they both save a princess
2. They both anticipate adventure.
3. They don't always consider the consequences of their actions or carlessness.
Meeko & Tod
1.They both wear red.
2.They both have black hair.
3.They both have long hair.
Belle and the Beast
1)They both get directly involved with magic of a form.
2)They both live a isolated life at some point.
3)They both have their dresses magically changed.
~Wendy & Mulan
Wow, I wrote three things before realizing you're probably talking about Wendy from Peter Pan, not from Gravity Falls. Oh well, I guess I'll post them anyway, since I already came up with them, if you don't mind (so this is Wendy Corduroy, sorry):
1. They both are tomboys
2. They both are good at fighting
3. They both are extremely determined
Let's come up with a weird, tough villain pair:
Yzma and Callaghan
1. They are considered a good character in the beginning by the main good character.
2. They both want revenge from a good character.
3. They make the main character stronger/nicer in a way by the end of the movie.
Thomas O'Malley and Baloo