Hidden food stash

Genuinely curious of strangers opinions on this.

My step daughter put on her Christmas list she wants her own stash of food she doesn’t have to share with her step siblings.

So for Christmas my husband bought her a “safe” with a lock code to keep in the pantry for her to have her own “stash”

He said the other kids are going to want one. I said yea, I’m going to shut that down here for the other kids because I teach them to share. When they buy their own food they can “stash” it however they want. But if I am buying the food it’s not for one person it’s a community food whoever wants it can indulge.

What’s everyone’s take on this? Am I wrong.