I have the 24C and it's probably a little heavy, although it feels heavier than it is due to the rear-weight bias of break barrels.
There are some youth air rifles designed specifically for youth like the Ruger Explorer, Crosman Raven, or Stoeger X3 although I don't have experience with any of them. I suspect they're all big-box consumer goods from Chinese OEMs at similar price points.
You likely won't receive any mail order item in time for Xmas though. I have an order from AGS that's more than a week overdue.
The Stoeger looks like it's available at the Canadian Tire in Castlegar, while the Raven is in stock with DL Airgun
The Trail store also looks like they have a few Daisy Red Ryders left (1 wood, 3 with the pink plastic furniture) which are, of course, seasonally appropriate.
Incidentally, Diana's youth model is the Model 11, while the polymer-stocked 24/240 is the Panther 21.