Cane here to say the same. There is also a fridge lock you can add to an existing fridge to lock your mom out.
She can access the fridge again when she can respect your parenting.
Message me if you need help accessing these items. I’m so infuriated for you.
If I were you, I'd stick a mini fridge in my closet (if you have one) and lock it. Then keep myself stocked, and what they do is up to them.
I have this for my office mini fridge lock