I don’t have children, but friends of mine with children tend to get up by 5 or 6 in the morning to exercise. It may be a challenge, but it may become a routine.
Do some exercises that are possible to do at home and make little noise in case the kids are sleeping such as pilates or yoga.
With just 1 simple exercise in the morning or the 7-min exercise in Fabulous. It’s the most that I can do in the morning. But when I have time in the afternoon, I do a bit more, especially in the weekends or holidays.