Look sweety, the only way to resolve this is to:

1) When she is going out, don't go with her.

or

2) If she asks you to go, say that you don't feel well and can't.

or

3) If you do go out together.... do not take your money with you.

or

4) MOVE OUT!

I am so sorry about this situation. Your mom sounds like the child to me here. You also should talk to your dad about it. Make him give you money for shopping.

When I lived at home, I used contribute to the household, especially food stuff. I would go food shopping for the house. It was not demanded of me. Maybe your mom is trying to tell you something here.... how old are you?