Here are some of the games I would recommend; has she played any of these?
Big City Adventure: San Francisco
Big City Adventure: Sydney
Mystery P.I.: The Lottery Ticket
Mystery P.I.: The New York Fortune
Mystery Legends: Sleepy Hollow
Amazing Adventures: The Lost Tomb
Mystery Case Files: Huntsville (good, but it is timed)
Those are all pretty much pure hidden object games, and I think she would like them. There are quite a few more that I could have added to this list, as well.