Keystone has a wide variety of blues. Spring Dipper is a gentle blue with one slightly steep part, same goes for Flying Dutchman and Wild Irishman. Paymaster is more gentle overall. Santa Fe, which starts halfway down Spring Dipper is always pretty empty--but it also has a neat "mining tunnels" for the kids. Bachelor is rated a blue, but it's pretty much 100% moguls. It is my favorite mogul run on the mountain. Mozart is a blue, but it's so crowded in some places due to its steepness that I avoid it at all costs. Instead we take Diamondback--one of two groomed black runs on the mountain--right next to it. There is a pretty long steep stretch, but it should be doable for anyone comfortable on blue slopes (just take lots of breaks). Both slopes are south-facing, so it gets really slushy after lunch. If anything, just take the gondola to North Peak. I also avoid River Run at all costs, too--if you need to get to that base, just take Schoolmarm to Ina's Way.

On North Peak, Prospector is a gentle blue run; however, Last Alamo is a pretty steep blue run. On Outback, Elk Run is a long medium blue run which typically has moguls on the right edge (the rest is groomed).

(I've been skiing for 39 years. I taught my kids to ski at 2 1/2. They are now 11 and 14 and can follow me on anything I do (including double blacks).)