As active as Taffy still is, I'm inclined to think a kitten might be too much for a 14 year old. She did get on with our old male when we introduced them two years ago (he was 18 at the time, lost his sister a few years earlier) but was perhaps a little too energetic for him.
I think she'd like a dog even more, but we're not prepared to get one at this time. She's made friends with two of the dogs that we encounter on our walks, so it's possible she lived with one before.
The orange female that our cat-sitter has rescued is probably out too. Although this one is much more handle-able than the tabby was, another very timid cat would probably be a bad idea.
The advantage of the local rescue group that we got Taffy from is, they have the cats living in people's homes or their own shelter so they can see if they get on well with others. The disadvantage, as we discovered with the tabby, is that after they've lived in this shelter or a foster home for more than a few years, they start to see it as home and it's a wrench to them to live in a new home. When the tabby was returned, she went back to business as usual at the shelter, grooming her boyfriend... it was a relief to know we hadn't traumatized her permanently but it also told us that she probably wouldn't accept another home easily unless the boyfriend (yet another jet black cat!) went with her.