It wouldn't have surprised Kat, nor offended her, if she'd turned around to find the other woman gone. Kat, after all, wasn't the most polite of people by normal standards either, and to just take off was something that she would totally do. Still, she also wasn't dismayed to see that she had waited, which was also a little strange. She tended not to care much about what other people did, unless she had to work with them on an experiment or something.
"Isabelle. Hello." She considered for a moment, then spoke with a faint tone of surprise, "It's nice to meet you." She didn't really tend to just mouth idle pleasantries, so when she said something, chances were good she was being sincere. "Yes. I'm a panther." She didn't tend to talk about it much, and it still felt strange, but the woman already knew, after all.
Her dark eyes brightened quite a bit, though, when the library was mentioned. "Oh, well then, I believe I will impose my company on you for a time, then. That was were I was heading myself, before I stopped for coffee. Do you mind if I join you?" The last was asked almost belatedly, since it didn't occur to her right away that it was possible that the other teacher wouldn't want her around.