The four places you list are very different -- entirely different price ranges (Jaguar Paw is maybe 8 or 10 times more expensive than Mida's), level of amenities, setting, location and in other ways. Clarissa Falls and Mida's are budget level (well, Clarissa Falls is more expensive than it used to be) in the San Ignacio area. Neither of these is in a "jungle" setting. The other three are in the Belmopan area. Jaguar Paw is a near luxury-level place (with even A/C in the jungle). Ian Anderson's has a variety of accommodations from camping to nice cabanas. Banana Bank is more of a mid-level lodge.
Depending on the age of your child, Ian Anderson's might or might not be appropriate. Younger kids may not be able to participate in the more rugged outdoor tours.
I'd probably vote for Banana Bank as a pleasant, moderately priced place with a lot advantages for families and kids -- horses, animals on the grounds, etc. But Ian Anderson's place could also work.
On a given night, any place in Belize can be sold out. That's especially true at peak travel times such as holidays and from late January through March. I would at the very least call ahead while in the country to be sure there is space available.
Belize books and publications by Lan Sluder:
Belize First Magazine (http://www.belizefirst.com
Fodor's Belize & Guatemala Guide (new 4th edition coming this fall)
Adapter Kit: Belize (the first and only comprehensive guide to living, retiring, working and investing in Belize -- a best-seller on Amazon.com)
San Pedro Cool (the first and only visitor guide to Ambergris Caye)
Belize First Guide to Mainland Belize -- sold out, new edition coming early 2003
UpClose Central America
Belize Book of Lists -- sold out, new edition coming early 2003
Best Hotels of Belize -- coming late 2002