How about UNA (it means "one") - since she prefers to be the only cat in her houseold?

Another suggestion is HANNAH SOLO (sort of a female version of "Hans Solo",again playing on the notion that she prefers to be the "solo" cat in her family).

Both of these names could help demonstrate to prospective adopters who see her name that she does need to be in a one-cat home.

(She sure is a cutie. We already have several kitties, though.)