Both of my sons and myself were earning money as babysitters at age 12. In fact, my son who raced bought his first bike with babysitting money. They are not that old that this was in the "olden days." I believe that kids today are WAAAY too overprotected. Of course, you need to teach them responsibility along the way, as they grow, so they are ready for the next step each time.
Tuckerville, take your in laws up on that offer. My husband and I didn't ride back when the kids were little, but you can be sure we went out alone or with friends almost every Saturday night. You do not have to sacrifice your own interests totally when the baby comes. Sure, I did all of the "mom" stuff, but we both worked, we spent time together without the kids, and my kids grew up to be very independent and normal adults despite the fact that their parents left them with a babysitter...
I only we wish we had taken up cycling when they were little and did the trailer thing, etc.