Welcome Chris to the EKN and karting community. Starting out with indoor karting is a great way to get hooked. Looks like you guys are ready for the next step.
The KartSport North America group at the GoPro Motorplex are among the best people to get you started in competitive karting. They deal the FA Kart and the Arrow kart.
My suggestion is to check out the chassis products they have available, and start off with the LO206 engine. This is very similar to the indoor karting engine, American made, can be raced right out of the box brand new, and is a great speed to get started. Then, if she catches on quickly and wants to move faster, you can advance up into the Rotax engine with the same kart.