I'm not really sure what the symptoms of leaukimia are, but they need to be seen by a vet anyway for a good check-up. I have read where you can carry stuff to your cat by contact with another. I'm always very careful not to let an outside cat rub up against me. I also wash may hands in hot water for about two minutes after I pet one. My experience with milk has been it sometimes upsets their tummy. I would say just have her check with her vet. Sorry I couldn't help more, but I'm sure someone at PT can. Good Luck!