Ayisha
Contributor
...3.) What did the beach situation look like? Is it a nice, gradual sand-slope to a wadeable, clear-sandy bottom (like kids play in, and some people hang out in), or is there iron shore? Any 'sand fleas' (I hear a lot about those regarding Roatan, but not Belize)?
4.) Did the topside on Ambergris Caye look like it had adequate entertainments for a spouse and little kid? Some touristy shopping, souvenirs, etc...?
You and your family might enjoy Placencia, which has beautiful, gradual sloping beaches, with children and adults playing and laying in and around the water.
We went in April 2019, and didn't have any issues with sand fleas, and I'm usually a magnet for them. I wore Sawyer's with Picaradin and my friend used Off with Deet when we went out at dusk (and remembered to use it), but I don't believe either of us got bitten. We were surprised at the lack of no-see-ums.
On Ambergris Caye in January 2006, I don't recall any issues with sand fleas either.
(Roatan is a different story. Most in our group of 14 had tonnes of bites with their low percentage (7%?) deet or no bug spray, except for the 3 of us with the old Cutters Advanced with Picaridin. Everyone was coming to us for spray by halfway through the week.)
Placencia is just a still up and coming beach town, but it has a long strip of shops with souvenirs, groceries, necessities, restaurants, and coffee/gelato shops.
It is also a day trip for you to get to IMHO the best diving Belize has to offer, which is Glover's. I of course love diving off of Lighthouse, especially Half Moon Caye, the Aquarium, etc., but Glover's reef is even better for the health and colour of the reef, as well as the abundance of large critters. Not as incredible as Jardines de la Reina, Cuba, but head and shoulders above most of the Caribbean. Thankfully it's far and off the beaten path, which helps to keep it healthy.
I haven't stayed on Glover's atoll, so I can't say how non-diving and child-friendly it is, but I suspect it's quite secluded with that much less for them to do, besides relax and explore, which just might be enough.
Hope that helps...