I recommend visiting Yosemite in the winter. Fewer crowds and more dramatic scenery. Just ask Ansel!
For a slightly challenging backpacking adventure with your entire family (kids 8 and up) start in Tuolumne Meadows and hike 2.5 miles / 1500 Elev gain to Upper Cathedral lake and then another 2.5 miles / 1500 Elev gain to Upper Sunrise Lake. Stay a few nights and then hike down 2.5 miles to Tenaya Lake. Don't hike the reverse route as the hike from Tenaya to Upper Sunrise Lake is a little steep. Bring all your backpacking gear including fishing poles and prepare for a great adventure. Prepare for potential mosquitos during some times of year and cooler nights above 10K ft Elev. No fires at Upper Cathedral Lake but fires are ok at Upper Sunrise lake.