Fix car for desperate family

My husband works full-time at a third-shift (night time) job with a wacky schedule. He's also studying to be an EMT, which means he's never home. I could work part-time and still care for our nine-year-old son if my husband's work schedule wasn't so unpredictable, but who's going to hire a woman who's been out of the workforce for nine years and can only show up, for example, every other Wednesday? We can't afford childcare. Recently, our sad old car stopped working and we had to borrow $1500.00 from hubby's not-well-off grandmother to get it running again. We have little hope of paying this back. Please help us repay Grandma and maybe give our very good kid the kind of Christmas he deserves.