That's one thing I've never understood about the U.S., this having to explain a gap in your work. I don't get why that's any of their business! Employers forget that without workers, they wouldn't have a business. It's become all about people begging for jobs and I just can't subscribe to that.
As for raising children, I think that should be pretty obvious when told to a potential employer and should need no more explanation.
Be patient and keep putting out resumes, you never know when the timing will be right.
In the meantime, I agree that you might want to start looking at a home business as an option. I had to do that because as you can tell, I have a problem with the system the way it is, so I decided to take my own fate into my own hands.
The good thing about a home business is that you don't have to JUST work from home, you can spend as much time as you need working from home, but you can also get out out of the house too. But your babysitting costs would be substantially lower than if you were to be employed full time. Let's face it, working outside of the home full time can be almost redundant after you pay your sitter. I know, I did it for many years and the pay-off finally came when I started working from home. Life changing.