Bombalurina is one of the non-spayed female cats. She is wicked, sexy, 
and wild. She likes to attract attention (especially male) but her 
biggest goal is to win Rum Tum Tugger whom she's all over, but he snubs 
her. (more to be playfully mean than to really snub her because he really 
thinks she's hot. He just didn't like the self-assured way she came on 
to him and wanted to stir things up a bit.) (At the performance I saw, 
the little revenge act she did at the curtain call with him was terrific!) 

It is my theory that Demeter and Bombalurina are definitely sisters! The 
way Bombalurina (obviously older) protects and sometimes wraps her arms 
around Demeter and the way they always hang out (and more notably, the 
fact that they have certain tensions I only have seen between sisters) 
would indicate a very close relationship. That and that they have very 
similar fur markings and even facial features indicating same breed and 
possibly same family. And they act very alike.

Bombalurina and Macavity were earlier together, probably as mates of some 
type. I think it was serious. She knows a lot about him and is not so 
afraid, and yet more fearful because she knows the truth. Some of the 
looks Bombalurina and Demeter give each other during Macavity's song indicated 
a tension. At first I thought it could be some sort of sexual rivalry 
over him. Now I think there is also the better possibility that Demeter, 
even though she was also once more or less in cahoots (maybe through her 
sister's contact) with Macavity, doesn't like or is scared of Macavity. Or 
didn't like Bombalurina's involvement. This also shows when the false 
Deuteronomy appears. Demeter and Bombalurina are not fooled for an instant. 
But Demeter is highly distressed and tries to reveal the fraud. Another 
notable thing is that Bombalurina tries to hold Demeter back and calm her 
and prevent her from attacking Macavity. Maybe Bombalurina's involvement is
not over.

But despite her seemingly wild and wicked nature, she sits with the old cats 
like Jellylorum and helps them look out for the other cats. She is one of the 
older cats (though not old like Jellylorum.) and her maturity places her up 
with the more respectable females. And she's wiser than some because she's
experienced and seen life beyond the sheltered litter which is why she feels 
like she should protect some of the younger ones from growing up too fast the 
way she did. She does not have a secure home or owner like Mistoffeles. By 
securing a place with the elders she is preventing Grizabella's (also once a 
glamourous sex idol) fate from happening to herself.

- Masked Rose