Go online to
http://www.annualcreditreport.com. Mom will be able to pull her reports from all 3 bureaus. Consumers get to do this once per year per bureau for free.
Accounts that are in trouble are usually listed first, and that can help her to narrow down which of those accounts have levied against her. The creditor info will be listed with at least an address, and often a phone number. Start there.
If you want to talk to someone at the law firm/collection agency, mom is going to have to call and cough up her SSN to verify that it's her. Typically, they'll only talk to HER, not you, since the debt is in her name (No, it doesn't matter that they have seized an account with your name on it - they can only speak to her about it, Once she speaks with them once, she can probably give permission for them to discuss things with you too - but it's going to have to start with a call from mom.)
In the meantime, open a new account of your own and start getting all of your funds pointed to that account because anything that goes into the other account (anything with both names) is going to be kissed goodbye for a while until either the levy is satisfied or until any mistake is cleared up.