I think you’re worrying for nothing. You’re allowed to run errands for your mom using her bank card.
Unless your college picks you for verification when you’re applying for aid I doubt anyone is ever going to ask about it. If you are picked for verification you turn in the papers the college requests. I think they wanted signed copies of our tax returns. I don’t remember them asking about our bank accounts.
Even though your name is on your mom’s account it sounds like the money in it belongs to her. So I think you did the right thing by listing it as hers. I wouldn’t edit your current application or make changes to the other two. When forms ask for the amount in your account you put the money that belongs to you. Can you empty your mom’s account and use it for whatever you want (like a fancy car or a trip to Europe)? If not, it’s not your money and you shouldn’t declare it as such.