Jean is a Telepath so she can read peoples minds, control their thoughts, create illusions. (I've been told this before.) She has used this power in the past to drop cars on bad guys. (Sweet!)
Jean was one of the original five X-MEN and is the lynchpin of the team, tempering massive power with warmth and compassion. She is married to Cyclops but sexual tension still exists between her and Wolverine. (Hey - aren't you Wolverine?)
Then a clone of Jean turned up, which had been created by Sinister... (Drumroll please!)