The only fem version I can imagine would be Sally-Anne, which you could contract rather sloppily to something like Solon, and which might easily be written down by a dozy clerk who noted what he thought he heard instead of what was probable.
Or, could the names be in the wrong order? KellySolon? Would also be an easy transcription error ... I've never seen Solon as a surname, but I haven't seen it all by any means. What an interesting discovery. Good luck!