Suggestions on how to keep my toddler from pulling her sheet off and eating her mattress ?

I've tried taping the sheet on I've tried doubling up on sheets, I've tried one on each side, I've tried wrapping it in a big sheet then putting her sheet over it she gets it out every time and has almost eaten half of the mattress stuffing out of it

Well I guess it wouldn't matter because the toddler bed has the same mattress

@beebaby they share

Is the baby with you or they share a room

@beebaby she hasn't been switched to toddler bed yet because she likes to pull shelves down and throw things in her sisters bed so we don't want her being able to get out and hurt the baby

Oh wow. Hmmm.

@beebaby still in her crib

They sell straps to secure the fitted sheet onto the bed.

Is it a toddler bed?

@beebaby turning two

How old?