I have the same problem, but I found a way to do some work from home, after realizing I was actually LOSING money each month last year!
It can be important to stay in the workforce, over the long term, but when you consider the $300 profit, make sure you subtract the cost of gasoline, if you have to drive there, clothes and other supplies for the job.
It may not be worth it. To spend less time with your child for just a couple of hundred dollars profit...
Try to find someone to help you out---another parent, friend, relative. Also consider other work options, and cut corners at home---shop at your local Goodwill store, spend less on groceries, cut the kids' hair yourself...