I have taken my 2 older kids to Co for similar trips. Elbert is an easy walk. That may be just what you're looking for. The 14ers site is really helpful for planning, selecting the appropriate climb, and getting info on conditions. My last trip there was in Weminiche of the San Juan's. Its a bit more adventurous than most of the collegiates I if you have the time or inclination.
Be aware of elevation issues. One of my sons had no issues and the other had to go back down for altitude sickness. There seems to be no good way to predict who will be affected.
One easy 14 area to hit is Mt Democrat and the other surrounding mountains. The summit is easy, short, and straight forward. You can make several other 14ers in one circuit if you're feeling it. You can car camp right at the base.