Maybe I am reading your post incorrectly but I am not sure why at this point she would need to be with kids who are 2-3 years older rather than just 1 year older in your current gifted program. Since she is already 7, I am assuming that she must be going into at least 2nd grade in the fall so the 4th grade math would be at most 2 years ahead. If she is in a program with gifted kids who are presumably at least a little advanced themselves and has outpaced the other gifted kids by one year, it may be best to simply accelerate her by one year in the same gifted program so that she does math with kids who are one year older. In our district, acceleration is not allowed unless the student is advanced enough to be accelerated into the gifted program, which works one year ahead with enrichment. You definitely don't want your DD to end up in a regular class with mediocre or poor students who are 2-3 years older.
