I would give Kindergarten a try, rather than repeating a year of pre-k. DD was 4y9mo when she started K, about 3 months after the cut off. She went to a full day private kindergarten, and she was initially wiped out after a full day. She hadn't taken maps since age 2, and she would take a nap after school. She was used to the schedule in 3-4 weeks, and it was the best situation for her.
If your DD enjoys school and would do well in a structured environment, I would choose the gifted charter school. She is likely to find other children who she can relate to and teachers who understand GT issues.
Jen
