I (somewhat) agree with Ozzie! Wow, someone else who actually thinks 
that Jemima is Demeter and Macavity's daughter!

BUT: I think Jemima was conceived against Demeter's will, but 
Macavity just didn't know. Demeter acts nothing like a mother to 
Jemima, which leads me to believe that when Demeter escaped from 
Macavity (I believe she was catnapped, not his mate, and she was 
forced to do whatever he wanted *coughcough*) and discovered she was 
pregnant, she got a bit.. freaked. So when the kitten was born, 
everyone in the tribe was told she was an orphan/abondoned. They did 
this to protect Demeter and Jemima from Macavity, who would most 
likely want his kitten to be a criminal like him.

About Demeter and Munkustrap: I honestly can't see them as mates. He 
was just doing his duty as a protector when he saved Demeter from 
Macavity. She might have feelings for him, and vice versa, but I 
don't see it happening.

- Jellicle Jemima