Crosbydog......I think Aloha pointed out a good point. Success in G12s does not mean much in developmental term, especially if your daughter wants to be a pro.
I have a couple of suggestions to add. First, you should make sure your daughter understands what the pro development path involves, amount of hard work, dedication over several years, etc. Also let her know that the chance of reaching her goals as a top pro and Olympian is pretty slim.
Granted that you already had Macci evaluated her and he saw no major flaw for a pro potential, if she is willing to put in that kind of work then you should give it try.
I am sure you read and did a lot of research on US women pros. Many recent pros I've seen or read about would be home schooled, play tennis several hours/day from middle school on. Many families did bring them back and forth for good coaching, private academies or USTA center in FL and trained full-time when they were a bit older. Look up Christina McHale, Lauren Davis, Sloane Stephens, Madison Keys etc. It is good that you are cautious and gauging how and when to proceed. If she continues to progress well, you should give it a try. It looks like you are not having Serena or Sharapova but she might be one of the above names. McHale is in this Olympic, you know.