I took my grandchildren to the Grand Canyon. My eldest daughter and my son-in-law also went. There's a hostel at the bottom known as Phantom Ranch. You're guaranteed a shower and bed and hot meals. We hiked down the South Kaibab Trail. At the time, my grandson was 7 and my granddaughter was 10. The little guy led the parade. We also hiked up the Bright Angel Trail to the El Tovar Hotel in the South Rim Village. That's 11 miles with a 4,500-foot elevation gain. My little grandson made it. He didn't set any speed records. But we're really proud of him.
Discovery: Yuma Point on the Boucher Trail, along the west side of the Hermit Creek drainage, is a lovely spot. You get a spectacular view of the whole canyon. It's very special. I don't recommend going there, however, unless someone [you're with] has a little experience.