I think the big issue with civilians and kids on starships is it makes more sense if the ship was doing a big deep space exploration for years and years out on the frontier and might not return for ages. If in the distant future NASA and the Airforce have been sending out colony missions to planets for a hundred years and then decide they're going to try one with families, I could see this happening. The Enterprise is out there all alone but is ready to defend itself. But I'm not really onboard with the ship being sent into warzones or other dangers that the head office knows ahead of time they might get everyone killed.