Hill style LB for 10 year old

[Collett5149]

I need to downsize my longbow design to make bows for 10 & 8 yr old nieces.
I'm thinking 15-20# ish, but don't have a starting point for bow length.
Any advice is greatly appreciated.
Thanks, Andy

[Kirkll]

The thing about kids is that they grow quickly , and outgrow their bows. So I wouldn't go shorter than 60". With a longer bow, as they increase their draw length, it increases the draw weight. .02 cents worth.