You say it is your SIL - how is this woman related to you? Is she your DH's sister or is she married to one of your brothers? Could you ask the blood relation how to proceed? Since you already made the top I believe that you may as well see it to a conclusion, or put it away and tell her you will need to wait to have it quilted until you can afford the $.... to have it quilted and see what they say. If they say, fine, no hurry, then you have your answer. Maybe they really didn't have any idea of what they were asking of you.