what an awful thing! I can only imagine how sick your sister is feeling having lost her apple I touch. I took out my cards to ask them what happened to it. While shuffling, the star card dropped. I take this to meaning that your sister needs to keep believing she will find it. When I first saw this card drop - it made me believe that she did remove it from the car herself and has just forgotten what she has done with it.
However, I still threw out 3 cards--
8 of swords, knight of pentacles rx, Queen of Pentacles
makes me feel that your sister took her apple I touch out and was not paying much attention to what she was doing. I think perhaps she was busy with a million things at the time on her mind. Perhaps she was with another person, or went into a building where there were others around and she inadvertantly put the apple down on a table or something and left it.
At any rate, the knight of pents rx is facing this 8 of swords, which means that someone is going to return this apple to her. Someone, I think she knows--and he/she has possession of it. However, perhaps with the busy time right now (just after the holidays-perhaps the snow and cold, if your sister is in one of the places w/this, etc), this person in possession just has not gotten around to returning it.
The queen of pentacles I believe is your sister being reunited with her apple. I feel like this will be done within a 3--as I keep seeing a "3" in my mind. Perhaps 3 days? I hope not 3 weeks. It may even be on the 30th or 31st of this month. I also feel like your sister had entered a place--perhaps a shop of some sort--where other people are, and this is where it was left. Maybe even a library or something?
The 8 of swords btw is also showing just how upset your sister is about misplacing this that she cannot think clearly of where all she was when it disappeared.
furthermore, I generally add the cards together for the number and revert that back to the corresponding major arcana. 8 + 12 + 13= 33. 3 + 3 = 6 and this is the lovers card. Perhaps she was meeting a friend when she misplaced hte apple? Or someone she works with? add the star card, 33 + 17 = 50. 5 reverts to Hierophant. Perhaps someone who is 'over' her--a boss? has this apple I touch? Just a thought anyway.
Good luck to her finding it!