S.S.
I suggest you look into some basic sewing classes. I don't know if you have a Hancock Fabrics or a Joann near you, but I know the ones around here offer classes.
You also likely want to get her a newer machine. If it's sat in storage 15 years, it's going to need a major tune-up, which can be just as pricey as a new, basic machine.
Wal-Mart sells basic machines geared toward teenagers. They're usually aroud $75-$100.