I have been a hiring manager off and on for 10 years. Gaps in a resume don't freak hiring managers out as much as you think they do. Honesty is always the best policy. You don't have to go into great detail, but acknowledge that you stayed at home to raise the kids. In order to do what you thought was right, you worked night jobs in addition to raising your children. Now, that your kids are of a certain age, you are flipping your work hours. Rather than working while they slept, you will work while they are in school.
Managers look for 3 things. 1) Do you have the skills needed to do the job. 2) Are you and honest and trustworthy individual. 3) Are you dedicatde to getting the job done.
If you "fail" on any of those 3, you won't get the job. If you pass on those 3, you move into the bucket of "who is the best fit." The key is to make it over the first hurdle.