I think I'd go to the store to see if she still works there. If she does, I'd express my regret that she is having a rough time and ask for the fabric and money back. If she balks at the money, I'd consider it a donation to the kids. I'm not a softie, but sometimes life is hard for young families trying to get by. I would give her the benefit of the doubt, but the fabric should be returned no matter what. If she doesn't return the fabric, then you might have to take further steps.