From everything I've seen, Arnold's wife was unknown. Some show her first name as Joan, but I don't have any records that indicate that Joan Cherleton remarried after the death of Sir John Grey. I haven't done an exhaustive search, so I'll wait for others to pipe in with an opinion. If no one does, feel free to detach Arnold de St. Leger from Joan (or let me know and I will do it).
Thanks for pointing this out.
Darlene - Co-Leader, British Isles 742-1499 Project