Okay, how many weeks did she receive into the wrong bank account? She filed her claim....I gather it was approved. So then she didn't get a check for ...... how many weeks? About four? And she was making the certifications, and the money that was being paid was not going in to the bank account she expected it to go into? Correct? How long did this go on?
How did she find out that the money was being misdirected into the bank account that I gather she was maybe having a prior claim put into? She worked with the agency, right? After all, the agency must have gotten the bank account information for deposit from somewhere. Has she returned to work yet? Did she get the error corrected?
So then, if all effort to correct the situation has officially passed beyond the agency's control, it would be a case of small claims. Do you know this is the case? I can't imagine that someone sat passively and wondered where their check was for several weeks, and then discovered that it was going into the wrong account, and then was just told "tough luck." There are numerous procedures to cover appealing all sorts of mishaps that may occur in the claims process.
Though the UIA can take money from people for overpayments and the like, they wouldn't ever be sending it or assigning it to someone else. I would suspect that the unemployment system has already given this person a very clear description of what has happened and what is going on, and they are now trying to figure out that they somehow didn't change away from this bank account, got several checks misdirected, and now there is no process to get them back simply because the unemployment agency doesn't change money out of one bank account and pay someone else just because they SAY they didn't want that bank account used after the fact without ever filing the necessary change paperwork.
If this was truly a result of a gross error on the unemployment system's part, not that the claimant didn't make the required changes, but that the agency just plain missed the requested change and failed to do what you'd instructed them to perhaps you'd have some appeal rights. That's what you need to find out from your mother.