Thanks everyone for the input! I'm going to work harder to ensure that Bianca has her own space and time to herself. I'm pretty sure that I wouldn't have been able to give her up regardless, she's just the greatest cat. Though now I'm a little concerned/worried that it may be because she's sick that she was acting up.
After spending the weekend at my mom's place I came home and Bianca seemed to be having trouble meowing, it sounded a lot like how people sound when they have a cold. When she purrs the same problem occurs. There have been times in the past where it was simple dehydration, but I tried giving her fresh water and everything - she's still having trouble.
I don't want to be bold and jump to conclusions like she's got a respiratory infection when the only symptoms thus far is her strange behavior and her trouble meowing.
I'm going to take her in to the vet regardless - better safe than sorry! - and see if they can put my mind at ease. I'd hate to have all three of them get sick and have the torture of getting 3 cats over a URI!
On a side note -- am I missing something about the Humane Society? I've always had the impression that they were a great organization...