Neil Gaiman? I think you may have confused him with Neil Innes who sometimes worked with the Pythons.
Maybe you had the name mixed up with Terry Gilliam. I watched a bit of Python last night on paramount, still rocks, even now.
I think that everyone has got their sexist memory filter switched on - what about Carol Cleveland? Edited to add: And Connie Booth, of course - and Lyn Ashley (less well known and always credited on Python as "Mrs. Idle", which she was at the time).