I'm guessing that if she is allowed only one pair of skis that she is in the Nancy Green League. All of the kids race skis seem to be pretty good. I would look at SL skis and perhaps a little longer in length than you would normaly get for running SL courses only.
This will give her a ski that should be a little easier to initiate turns on and yet have a little extra stability from the length. The added benefit is that if she moves up to K1 next year and can have two pairs, those skis can become her dedicated SL skis.
We have had a lot of the Atomic SL & GS 11s in our house and my daughters quite liked them. I have some reservations with the Atomics as the recommended Boot location is a little further back than on other brands. Other than that the skis are very good.
The best local deal in the Toronto area is at Corbett’s in Oakville. Nordica Dobermann JR, one pair SL and one pair GS plus bindings, Marker JR race $499 for the set. I don’t know how much they have left as these are last years skis.
For used kids race boards try the Milton Heights Race Club ski swap, it is a very large swap and has a lot of kid’s race gear. The kids stuff goes fast, Friday night and Saturday morning are the times for the best selection. Nov 3, 4 5 for the Swap.
One caution is that you have to watch binding compatibility. At 100# she is probably close to, or already in a boot that has an adult type sole. I think the change in boot sole occurs around size 23. The Adult sole is wider and does not fit properly into Jr. bindings. You probably already know that but it is a detail we can forget, or at least I have been caught by this one.
Finally I have a pair of used Atomic Jr. GS 11s in a 150 length, Look Nova 7 Jr. bindings going in to the swap if you are interested.