I think I'd email her telling her that you understand that she's busy and hasn't had a chance to get to the curtains so you'll pick the materials up Saturday and work on them yourself. That way she maybe won't feel awkward about not getting it done, and you can get your materials back easier. If she doesn't have the $10 to give you, hopefully she spent it on groceries for the kids. Don't condem her without knowing the story. Life happens and mistakes are made. She probably thought she could do it for you and found out she had no idea how to do it.