I would definitely appeal, especially since her ability scores met the requirements. If you've had older children in the program, do you know the GT teacher/coordinator? If so, I would call her/him up and explain the situation and see if she/he will advocate on your dd's behalf.
A side note: I think the use of some of these tests to determine access to gifted programs is misused. There have been studies showing that OLSAT/CogAT tests do not identify certain kinds of gifted thinkers. On the other hand, it is ridiculous to exclude a child based on achievement scores if there ability scores are high. If you are going to do that, then don't even give the ability tests and just base access on achievement. The point of giving them both is to give two different snapshots of the child's ability. Combined with an honest thoughtful teacher observation (and I actually think they should include a parent observation as well, but they don't usually trust us!) These three things together can give a good understanding of the child but excluding based on one makes no sense. I think it takes more work and effort to really get to know kids enough to make an intelligent decision and many schools just don't take the time to do this. I am so thankful that my DS's school did do this for him and did not exclude him based solely on CogAT scores, which were not at all representative of his abilities.
I also agree with Grinity, regardless of the GT program decision, they need to meet your daughter's educational needs.
