Okay, this is a new idea for a book that I've got (I'm sorry if my english is bad.. I'm really writing the novel in Norwegian!)

The story is about a 15 year old boy. He lives with his mother, which is a single parent. The boy never knew his father, whom ran out of his mother as soon as she got pregnant. The boy's neighbour, an old, nice man, is however like a father to the boy.

Well, here it goes. I have a book idea which refuses to form further from that. It's about a young girl who can read the minds of others. But every time I try to expand that idea into an entire scene, I fail. Small options come into my head like she meets a boy who also is a mind reader, she over hears a man thinking of murdering another, ect... I need help/advice on how to take this small idea, and make it into a book. Please&thankyou.