Firestarter

First, a man and a woman are subjects of a top-secret government experiment designed to produce extraordinary psychic powers.

Then, they are married and have a child. A daughter.

Early on the daughter shows signs of a wild and horrifying force growing within her. Desperately, her parents try to train her to keep that force in check, to "act normal."

Now the government wants its brainchild back-for its own insane ends.