Disney Princesses and the My Little Ponies they collect:

Snow White: g1s, loves all of them and doesn’t mind if they’re not mint

Cinderella: g1, g3 and g4 but only MOC

Aurora: g2s, no matter how beat up they are, she’ll take them all

Belle: g4s, owns all the international releases and  wants complete waves of all the blind bags

Jasmine: All gens, but they MUST have all their accessories.

Ariel: g3s only. Largest collection of Mcdonald’s ponies you’ve ever seen.

Mulan: Will hunt down every piece of merch available. Owns more merch than ponies.

Pocahontas: g2s and all the g1 wingers, and only loose.

Rapunzel: g4 and g3s. Also makes pony art.

Anna: Loves g4 and g3.5, doesn’t care about complete sets and just buys whichever she thinks looks the cutest.

Elsa: g2s, especially the Europe Only releases.

Merida: g1, and she will hunt down your Nirvanas.

Tiana: Actually just helps the others out in their quests for ponies.