Plenty of firewood at Merriam, limited firewood at Pass Lake. Not sure about fish in Pass Lake, didn't have the poles that day. The hike to Pass lake is twice as long as Merriam. Very pretty area, same trail as Leatherman.
Other ideas for kids would be Langer Lake
(Cape Horn area), Baker Lake or Norton Lake in the Smokies, Farley Lake
or Hell Roaring Lake in the Sawtooths.
How's the trail the Heart Lake in the White Clouds? I'd been wondering about that one for a trip with my kids.