I have this problem as well, three kids 2,5,10 and I have to keep my work outs to after 8:30 pm,..my hubby works long hours and I dont expect him to do the bedtime routine all the time for the lil ones. When I first started working out I would be buzzing for an hour or two afterwards, however I think my body has adjusted and I get to sleep better and actually have a better sleep.
I have tried excersize with the kids thing,..but so often you hear "I am bored , I am tired, or they stop to pick every dandelion along the way". However, most gyms have a daycare right in them though,..however I love having that complete alone time.
You really have to do what works for you, and even though morning work outs are optimal, I think consistency is just as important. Regardless of the time of day, as long as you feel healthier, and you get the bonuses of inches or weight is coming off,..that heart rate gets up and you break a sweat,...just keep doing it....and have fun