Your plan sounds just fine. Kids bows might not strictly need 2" fadeouts, but all good, either way.
I usually do one of two types of kids' bows. Longbow-style, I go 1" wide to start I leave middle 4" alone. I make a mild front/back taper, say from 3/4"-1/2", and a mid-limb side taper down to the nock width, which is usually more like 7/16" wide. Then I plane off all four corners to an octagon and see what I got. It's usually bending too much in the middle, so I scrape all the facets except the back evenly, until it comes around like a longbow and smooth off the corners gently. It's funny because I bet I could barely pull off a 72"/50 lb longbow from good oak, but at 48" and 20 lbs at 22" it works just fine.
The other is more like an American flatbow. Add a little handle, make some fades, etc. If you do a straight side taper, go to even narrower tips.
The best thing about a 3" board making a 1" bow is that you can take the really, truly best part of that stave out.