: Sorry, my biggest concern is the height of this boat, would a
: reduction of an inch amidship and 2" at the stem ruin the
: boat for my smaller girls or improve the kayaks?

Kids are shorter than adults. This translates to a lower center of gravity so they can use a much shorter boat than the one you are thinking of. Their wingspan is shorter than adults so they need a narrower boat. They have less strength than adults so they need a shorter boat. At 5'9" and 180 pounds I could paddle the boat you mention only I wouldn't want to because it is at least three inches to wide for me. Adults, even large ones, paddle eight foot white water boats with ease. For a kid the boat you mention would be a lot of work and you might find you are going paddling by yourself.

If I had a daughter the size of yours I would make them a Kidarka by Tom Yost.
http://yostwerks.com/Kidarka.html

Tom also has two more kid size boats to make your decision process harder. The Sea Flea is a good one.
http://yostwerks.com/SeaFlea1.html

The Sea Pup is nice, but it may be a little long.
http://yostwerks.com/SeaPup2.html

Tom's site is at: http://yostwerks.com/

The paddle is very important also. You need to find a paddle that is sized for small kids. Better yet, make Greenland paddles for them from a 2x4.
Paddles that are too big are a lot of work for a kid.
http://www.qajaqusa.org/QK/makegreen2.pdf
http://www.youtube.com/watch?v=_7twy95IdtI&feature=gv#!

Remember, fun not work. Adults paddle to have fun, not work, and that's what the kids want also.

Best wishes on your project.

~Bob