I will repeat though that someone who is the legal POA cannot just hand it over to someone legally without the original POA being revoked and a new one drafted or a guandianship established. It sounds like this is what happened. Until the old one is revoked, it is still legally valid. And that is how banks and other financial institutions will view it.
A lawyer is not mandatory but can be helpful if you choose one with skills and knowledge in the POA/guardianship area. Many firms set aside a percentage of their cases to do pro bono (without cost). Many firms will meet with someone once without costs as well. Check with the Florida Bar, they maintain lists of lawyers, and the areas the are competent in.
http://www.floridabar.org/tfb/flabarwe.nsf
I don't think this requires anyone knowledgable about jw doctrine/policy but rather about the real issue seeing that your mother is taken care of by people with her best interests.