I'm in the same boat as the OP, only X 2, as my twin daughter and son just joined an archery class and now want their own bows. They'll be 12 in June and I'm worried that they're on the cusp of being too big for kids bows, especially my son who is about 5' 1" or so and about 140 lbs.
I've been eyeballing the PSE Mini Burner, the Bear Cruzer and the Ruckus by Hoyt, but haven't settled on anything yet.
