Thanks, everyone- Freedom especially, lots of great tips. I already started watching her feeding time and putting her bowl up when she's finished on top of giving her less food instead of completely filling the dish and leaving it out all day. I leave out her water, just not her food. I'll check out diet cat foods, and start feeding the cats seperately if this doesn't prove to be affective.

I don't plan on letting her outside, and she was just at the vet about a month ago for a cold- the vet checked her out for everything, so no thyroid problems!