It's better to do a more serious workout at the start of the day and then a few short bursts of home workouts(just 10-15 minutes) right before going to bed.
It's scientifically proven to be more efficient and the short bursts of exercise right before bed gets you extra tired and you fall asleep right away.
Hope it helps.
Also, have your clothes, mat, equipment (if needed), and workout video or plan ready. So, there is minimal thinking needed before starting.
Set an Alarm labeled work out for the days you want to work out.
Finally, as Mel Robbins says, when it's time to workout just count backwards from 5 to 1 and just do it.
Other ideas would be to involve your kids in your workouts. An iPad always works to keep kids busy.
Also, if walking isn't what you’re looking for maybe start small. If you are home with the kids watching tv, find a way to get some yoga in or do sit ups or push ups. Kids are impressionable and this will be great for them.
Whatever you do, start small and give yourself credit for any action you take!