I also am(was) a single parent. I had three boys, now ages 28,30, and 33.
There are definately ways to make money, and you can do it while doing other things. I can help you with some ideas, but I need to know where you live, and what kinds of things you and your kids do for fun. I am close to an expert at turning the things that you like to do, into how to do them and make money doing them at the same time.
For one thing, small things, like collecting alluminum cans, can help with the small expensis. I catered. I would do company bar-b-ques, and would spend about $125 on the goods for the food, then charge $6 or $7 per plate. If 200 people come, you have turned your original money invested, into $1200, for about 3 or 4 hours of work, and you get the leftovers to take home to the kids.
If you want to, get in touch with me at firstname.lastname@example.org and we can work it out for you