Well, the vet confirmed that she's a girl, so Maria is definitely her name. She weighs 1.6 pounds and is approximately 6 weeks old, so we gave her a birthday of April 1. And she's healthy! She was so good in the cat carrier and in the car - she just seems pretty calm and unflappable for a kitten. She didn't object to the vet messing with her either.
She's too young to start getting her shots, so I'll take her back in three weeks. Now we've just got to bring LuLu around. They are "visiting" under the bedroom door and LuLu continues to hiss. I got some great advice from the Slow Talk pet blog about how to help LuLu accept the new member of the family. It might take some time but I have confidence that LuLu will come around, because she is really such a loving and sweet cat.
When Maria and I arrived at the vet's office, we had to sit in the car for about ten minutes until this incredible hail storm passed by. I've never seen anything like it - walnut-sized hail was coming down so fast that the ground became completely covered and it looked like it had snowed. And the hail hitting the car was so loud, but Maria just sat in her carrier and looked at me and didn't seem scared at all.