Kerripat - we are doing that with my daughter and she is loving it. I think it is better than lessons for her because she is in control.
Sydness - you will be surprised at how much above grade level material a gifted child can absorb. I sometimes have no idea where my kids get some of the stuff they have in their heads. That is part of the point. Smart kids can learn what they are taught. Gifted kids can often learn without being taught.
Just a warning though - my DD was an underachiever and she didn't blossom until she decided that she was ready. We just found ways to reward achievement (paying for A's to get her to do the boring work) and found ways for her to really achieve (the elementary school science olympiad in our case). So, the first two times that we coughed up and paid for testing, it was a total waste of money.
Just saying - don't be discouraged if an underachiever underachieves when you are paying for it. Keep giving your child opportunities to achieve and motivation for achieving. She'll bloom when she is ready.
Mary