Anyone have experience with taking a parent off of account? Mom took money without asking.

My dad made my USAA account when I was a teenager, and both my parents were added to it. They’re split now, and I’m okay with my dad having access to my account, but my mom recently took a small amount out to “pay off her credit card” without asking me beforehand, but instead told me she took it afterwards. I suspect she was testing the waters to see if she could actually do it.

Does anyone have experience with taking a parent off of their account? Was it a pain? I’m going to call them tomorrow but have been curious if it’s possible or if I’ll just have to make a new account or something.