First off, relax. LOL. I have had my cat since she was a kitten and I was 5 y.o. She is the sweetest thing. Every cat is different. My grandma's cat doesn't like to be held, she's more of a loner. My cat loves it when I hold her or when someone she knows well holds her. If someone she doesn't know very well holds her, she will tolerate it for a while, but then want to be put down. A friend of mine's cat is VERY friendly. I was over her house last weekend for her birthday party. We decided to have a wrapping paper fight. This cat laid in the middle of the living room just looking at us like we were idiots while huge wads of wrapping paper were flying in every direction.
Sophie and the cat will be fine together, I'm sure. Just keep an eye on them at first to make sure they are ok. We got our dog, Jake, when Sassy was about 5. We had another dog at the time, too. Sassy and Jake were fine with eachother, but Sassy wasn't too sure of having a rambunctious puppy in the house as shes never experienced anything like that before. At first, Sassy was wary of Jake. Now, Sassy greets Jake like theyve been apart for years even though they may have just been across the room. Sassy will go up to Jake and rub her head against Jake's legs.
When you get the kitten, it may already be litter trained. If not, all you have to do is put it in the litter box and hold its paws and dig with their paws. The kitten should catch on pretty quickly if you do that a few times. My grandma's cat was a stray when we took her in. I did that with her maybe two or three times and she never had a problem.
You do not need to take cats to the groomer. They generally will clean themselves. Sassy is 11 y.o. now and I have never given her a bath or taken her to the groomers.
Most cats like anything with catnip or anything on a string. My cat loves cat nip, but would much rather play with a ribbon that I'm trying to use to wrap a present or my shoe lace when I am in a hurry. My grandma's cat loves these little plastic mice. She bats them all around the house and has the best time with them.
The kitten probably won't eat Sophie's food as long as you make sure it has enough food. Sophie might try to eat the kitten's. But if she has enough food, then she probably won't try. But of course, if either one is a pig like my dog is, then they will try to eat the others food. Dog food is specially formulated for dogs. Cat food is obviously specially formulated for cats. They will not get sick if they eat eachothers food occasionally. However, if you always feed the kitten dog food and never give it cat food, then you will have problems. And vice versa, if you always feed Sophie cat food, then you will have problems. If the kitten is only eating dog food and no cat food, then its not getting the nutrients it needs and, like I said, you will probably have problems. And vice versa. As long as you feed each one of them their own food (dog food for Sophie and cat food for the kitten), they will be fine. At first, you may want to get kitten food. Or better yet, get whatever the coworker is feeding the kittens.
I have never looked, but I'm sure they have cat clothes. The cat and Sophie will probably be about the same size, so even if they don't have special cat clothes, then you can get small sized dog clothes.
Oh, and one more thing. Get the kitten spayed ASAP. My cat was having problems going to the bathroom all over the house. She would even go a few feet away from her litter box. Once we got her spayed, she was perfectly fine. She may have had one accident in like 2 years. But she was 9 when we got her spayed and I was so scared. LOL. She is my baby, in fact shes sleeping on my bed right now. HEHE. When we went to go pick her up, we got stuck in traffic. It took all I had in me to restrain myself from rolling down the window and yelling at all the people to just drive cause I want to go get my kitty. When we got her, she started meowing from inside her carrier the second she saw me. I couldn't take her out, though, for another 10 minutes. That was the most stressful 10 minutes of both of our lives. LOL.
What are you thinking about naming the kitten?