Agree that the best starting option is the LO206. I just started in Jan/Feb of this year and bought a super clean used Intrepid with a PRD Fireball 125 on it. Did a few practice days and 1 race with the PRD just for fun. Then switched over to racing our Clone class. Didn’t take me to too long to be swayed by the LO206. Now I’m running our Box Stock Animal class (Basically a LO206 with the 12000 rpm coil.) It’s a blast and the competition is really close. The class is not just for beginners, we have a guy that’s been kart racing non stop since 1992!
Sounds like you’re going in the right direction. At first I was wondering why you didn’t just join GoPro. Then I looked at their site, it looks like a great place. Makes me really happy about our Club/track in Texas. Our membership costs only $315 a year and you get a key to the track.
I don’t think you could go wrong finding a used chassis and putting a LO206 on it with whatever restrictions there will be for her age. Then as she gets older you’ll be able take the restrictions off and continue to use the LO206 in any age category. With the LO206 basically all you have to do is change the oil, clean the air filter and clean the carb once in awhile. It should last for years. The focus will be on smooth driving and kart set-up.