I've had friends call me for cat advice. (That's how we ended up with two kittens last summer.) When my college roommate who lives about 45 minutes away adopted a kitten in her yard a few weeks ago, we went to visit. Her grandkids had found the kitten and named her Dottie. She has dots all over her tummy. Our friend has an older cat Baler who is about nine, also a rescue. Before a vet visit, Dottie was living on the screened in porch and Baler inside. However, my friends were going on a planned vacation. Baler and Dottie would be inside together. Fortunately, from the beginning they got along. Yes, Dottie annoyed Baler but, as a big brother should, he put up with her antics.
They weren't going to have anyone come in every day. With a six-week-old kitten, I couldn't stand the thought of her going without cuddling and playing. Kittens are a lot like kids. Early socialization matters. So we volunteered to help out. We found out when their relative was coming in to feed, and we traveled there the other days.
By staying a few hours each visit, both Baler and Dottie came to know us. By the third day, Dottie was cuddling with me. She napped on my neck and played beside me on the sofa. Baler jumped up on my husband's chair for some petting.
We'll have to visit Baler and Dottie soon to see if they remember us!