Use your skills and ask questions to work out which character it is you're trying to find? You can ask one question at a time such as "Do they have long hair?" or "do they have blond hair?", but not two attributes at once like "Do they have long, blond hair?". Oh and don't try to cheat as your opponent will know! Though she does play fair.
Use phrases such as "Are they a...", "Are they wearing", "Have they got" etc... to remove features. When you think you know who it is say "Is it ...." followed by their name.
A great way to pass the time, and you can involve other members of the family.