I think it is too late to mention anything about money. You might consider contacting her and telling her the quilt is done and was she going to be traveling in your direction or had family member going across country that could deliver the quilt otherwise you will mail it when you have the extra money and then wait a month or 2 before you mail it. I admire you for making the quilt you are truely an angel. Just be prepared if other family members ask for one to discuss costs and say this one was a effort between you and your niece. That way they will think niece helped pay for it but in truth the effort was picking pattern.