Our full-day guided tour of portions of the Everglades was quite a day (all 12 hours of it!). My husband and I did this tour with our 14 year old son. Great outing for kids. Each kid is different in their interests and abilities, so consider this before taking yours.
Folks of all ages should be prepared for and comfortable with getting dirty and walking in water up to your calves and mucky mud (at least this was our experience in the "dry" season, early April). You will need water shoes (they have all sizes if you don't have your own). For some mud is fun, but not for all. For myself and our son, it was worth the dirt because we got to learn so much and see so much nature. My husband probably would have been fine just on a boardwalk tour - but that's just his style. We all really enjoyed the kayaking (about 1/2 the day included kayaking). Our 14 year old had his own kayak, but if he were 10 or younger, I would have kept him in a tandem with a parent. Again, condiser each person's endurance level.
We were expecting Garl, but Don (a snake/frog researcher) took us out and he was an excellent source of information and a very nice guide! He knows the paths well and we felt very safe with him (considering this place is teeming with alligators).
Watching the sunset from our kayaks was a highlight. So awesome to just be there quiet in nature. Another highlight was the night walk on the Anhinga Trail. Very cool!
NOTE: The folks with us that only did a 1/2 day tour did not get to do the sunset or night walk. Too bad!
Highlight for our taste buds was the stop at "Robert Is Here". WOWWWIE! Wish we had all that delicious fruit in the Upper Midwest (they do ship!). Guanabana milkshake was amazing. Have you ever heard of Mamey Sapote? Try it! We reutrned the next day for MORE YUMMINESS!
If you are looking for a good, educational family trek though a unique setting, and you have an appreciation for nature, I would recommend this tour if it is in your budget. You will remember it for a lifetime!