She said her bar card didn't have an expiration date.
I took this as meaning that she might not be back to practicing law but the bar card she had that ID'd her previously as a lawyer doesn't expire and she never got rid of it. She used it fraudulently to present herself as a lawyer and gain access to the prison.
Yeah, her unexpired license definitely got her in the door to see Jimmy and to have some privacy.
And technically she could have represented him. Practically, though, if that had been tried I expect that hell would’ve rained down on them considering her relationship with him during his crimes.