Toddler pillow

Anyone’s June baby not wanting to use a toddler safe Pillow. For her birthday we allowed my in-laws to get her some cute frozen 2 themed sheets because she loves Anna & Elsa. Well the set came with a pillow case & after doing research I found out that it’s ok & safe to give a 2 year old a pillow so we found some safe ones. We put it in the crib with her and no matter what I do she always ends up moving it and just laying on the mattress. She’s a belly sleeping, always has been, but idk if it’s just her or if anyone else is having this trouble. Thanks 😊