If the tick has consumed the blood of a person infected by a blood born disease it is possible. Now if it contains lyme disease it is also possible. Now most organisms cannot survive the trip through the stomach acids. This includes diseases, but that doesn't mean they can't be absorbed through the stomach lining, this includes Herpes, and other viral diseases. Also, if the tick was carrying any stomach diseases, such as anthrax, E-coli, or Salmonila it's possible. If she has already had it in her system for a few days and hasn't shown any symptoms you can rule out the stomach diseases and lyme disease. Ticks can't survive without air, and won't survive in hydrocloric acid. So you shouldn't have much to worry about. Just allow it a few weeks to pass, if she doesn't show any illness then you should be alright. Anyway, Aids won't survive outside the human body for more than a minute or two, this includes in the stomach of a tick. So if she doesn't develope surface skin sores or leshions she should be just fine.