Hi.

My female cat has been acting weird lately, and my sister thinks it might be kittens.

She's been really mean to our dog, practically starves for my attention day and night, and constantly meows for me to follow her to a space in the closet that's basically hidden from prying eyes.

Is she pregnant?:confused:

It's impossible to tell from your description. These three symptoms my simply be that your cat dislikes the dog, wants affection, and likes to stay safe in private spot.

Have you not had your cat "fixed" ?

It sounds like she's in heat.. but I only say that because our cat did the same thing and she ended up being in heat then pregnant. So it could be either.. I would recamend getting her fixed if you don't want kittens..

Cats generally seek out secluded places to have kittens. If you feel her belly you will be able to tell depending on how far along she is. Was she in heat recently?