When I first brought Jake home, my son was still living at home and had a cat. Jake loved the cat, but the cat "tolerated" Jake. He would try to jump and play with the cat, but the cat really wasn't interested in playing with him. They did, however, kinda become buddies and would nap together. My son moved out on his own and the cat went with him. Jake seemed to miss him for about a week.
Honestly, if you are thinking of adding another pet as a playmate or companion for Lilly, I think another yorkie would be a better choice than a cat. I added a second yorkie, and they have so much fun playing together. My son's cat liked to play, but not with Jake. I guess it depends on the cat.
Just keep in mind that two yorkies means double vet bills, food, etc. If you are okay with all that, then you will love having two. They are also double the love and fun!
Good luck with your decision.
