OP, SOGGIE'S suggestions are pretty good. If you take on duties like that, I would also suggest sending quarterly (or however often is most convenient) updates on your actions on her behalf, so she stays informed, both for her sake, and yours.
You can never have too much in writing.
I might also add, as a security measure, when sending her copies of updated documents that bear her Soc Sec Number, redact all or most the the digits. Some penal institutions have unscrupulous staff and/or inmates processing/handling inmates' mail. You can provide her with the actual un-redacted documents upon her release.