I like this Small Poppies article for framing up some of the concepts: http://www.davidsongifted.org/db/Articles_id_10124.aspx
If you search for "gifted underachiever" you can find reams of articles.

People are motivated to get rewards in tune with their efforts. If there is no challenge, then a reward or accolade becomes meaningless. She can't exactly rise to a challenge if there is no challenge. And then when does one learn to try (grinding is not trying.)