Up until I got a full-time after college, I only had a bank account connected with my mom. Once I started working I opened a new bank account with a different bank which became my primary account. I didn’t close the connected account but I would always keep a certain amount of money in it so my mom could take it from it whenever. She’d always let me know when she’d transfer and would always put money back in a few days later (though she didn’t have to do that). Maybe you could do something like that.

Also, it sounds like your parents need to learn how to budget.