Amy,
I have two Convertibles and two 10.5's. We live on the Caribbean Sea and really enjoy our kayaks. I do kayak with my children in the Convertibles, but would find it very difficult to paddle with a child in a AF 10.5. The cockpit opening is large enough, but paddling would be difficult. I would suggest a two person kayak if you plan on always going out as a pair. I also paddle my Convertible solo (and enjoy it like that), but I think it would be a little less enjoyable if I was not as stout as I am. If you are planning on going out solo quite often, I would suggest the 10.5 or the Expedition. I recently saw a picture of a man paddling his AF Expedition with his little boy in it. You can see the picture on one of the last pages of Pearly's Fishing thread located somewhere around here. I hope this helps, a little, in making your decision.
Daddy-O
***EDIT*** Here is the thread I mentioned:
http://www.advancedelements.com/phpBB2/ ... &start=150 The pictures I mentioned are on page 11.