I live in a studio apartment, so I really can't do proper introductions either.
Paizly can be rather cranky about me bringing home foster kittens, but she doesn't really DO anything about it (other than stay in her bed and hiss and growl).
Nebbie LOVES having new playmates, though. A'course, she'll start playing, then when it gets too rough (yes, with kittens half her size), she starts growling and comes running to me "Moooom, they're being mean!" ...well, YOU started it! LOL