One of the problems with this can be that although the academics are at a higher level at her state school, her fellow students will still not necessarily be her intellectual peers. That is one of the things my kid loved about the Davidson summer program was meeting other kids like herself.
I think you really need to balance a lot of things. (1) What exactly are you trying to accomplish by having her take local college classes – acceleration in subject matter, avoiding boredom in high school, what else? (2) What the long term plan for her education if she does this? Is she helping or hurting her chances at attending an elite college for her undergrad degree or graduate school? Could she end up earning a bunch of college credits that don’t transfer to her final undergrad institution, if it is a different school (that can happen at top schools)? Is that okay with both you and her? (3) Can you achieve your goals in a local high school (either private or a public with a strong program, maybe an IB program) and supplementing with summer/EC activities? There are a lot of ECs that are great for gifted kids at the high school level – debate, speech, music, Quiz Bowl, Academic Decathlon, History Bowl, Robotics, Math competitions, science olympiads, science competitions, etc.