A quilt is a lovely gift but involves money and a lot of your time. My choice would be to consider how close you are to the recipients. Some would appreciate your efforts, while others would simply consider it a blanket that you might be better--and easier/cheaper--to find in a local store. A purchased blanket can be exchanged if not to the likings of the couple. I would consider if the couple would appreciate, not only the gift, but the time put into creating it.