My mother had dental work done about a year ago. She was waiting for her social security check when all of a sudden, it was frozen in her account. I checked into it and people say that lawyers can't freeze ssI income, is that true and what do I do about it??

Its partially true. A judgement for unsecured, non governmental debt cannot be used to garnish SSI payments. However, once those payments are deposited into a bank account, they become commingled funds and the bank account can be attached. There are several threads here that have dealt with this issue.

You can go back to the court and ask that the attachment be vacated on the grounds that all the money in the account is from protected sources, but you will be required to prove that with several months of bank statements.