Well I'm a single mom of 2 kids and I have low income and we don't any money to buy a car

I know that Goodwill Industries has a program that they will sell and finance an auto that was donated to them. The only stipulation is that you have a job. Call the local Goodwill office near you and ask about this program.

Yes the economy is tough right now, there is really no one that will give you a car, unless it is someone you may know that is willing to help you out.

There are various charities that help people with various levels of help. Do you have a place of local worship, or friends at work that may help