Wow, your 9yo can competently handle the gearing decisions of a triple and also use downtube shifters? Keep her at it because thats some serious talent that could be developed if she enjoys the sport.
A lot of adults dont understand the gearing options of a triple and a lot more fear using downtube shifters due to having their hands off the bars. A 9yo doing both is impressive.
I just switched my 9yo's bike to a 1x9 to eliminate the need for trying to figure out what gearing combo to be in at any given time since the original 3 ring crank was too much.
I look forward to her riding fast enough to benefit from a road bike's positioning.