can you make it a family thing? ive seen it happen with the guys quitting also, although not as often!
spend some time climbing on your own, with the guys, but get a kids full body harness and spend some time out with the kid on the rock. let the wife know that when you go as a family, it will be more about spending time with her and the kid. eventually she will (hopefully) come around. took about 10 years for mine!!!! but now i have 3 girls ages 8,9, and 13, who love to climb.
things change when you have kids, but they dont have to stop!!
good luck.
dave