It's been a few years.
If you are looking to acclimate to elevation or do family friendly trails with younger kids, there are paved trails (Snake River) that run through Keystone Ski & Golf Course. At that point you can either take Dillon Reservoir path into Dillon or take Rec-Path over Swan Mountain. It eventually dumps out on HWY 9 which goes between Frisco & Breckenridge. Would consider this a "Suburban Hike".
In Silverthorne there is the Ptarmigan Trail which is around 13 miles out and back. There is also a shorter loop that doesn't peak.
Also, Colorado Trail (which is about 480 miles long) Segment 7 goes from Gold Hill (Between Breck & Frisco) to Copper Mountain. and is 13+ miles in length point to point- it would be an all-day hike and is moderately difficult due to elevation gain. Can always have group hike Segment 7 and those who don't want to hike spend day at Copper Mtn or meet there at end of day.
As another poster mentioned. Can do Mount Evans or Evans/Torrey if you are interested in doing 14ers. BTW you can drive to Mt. Evans peak, but the access road is back on I-70 toward Denver.