Hi, I hope this is helpful. I have made many quilts over the years for Display Homes and Art Unions. They all tend to flatten when they are on the bed. Most that I made had to have four inch thick tontine to pad them and even these would flatten. Some were made from very expensive silk and were screen printed. One quilt had a huge bird of paradise in the middle and just the quilting alone took me four days. How about placing your beautifully made quilt for your MIL on your bed for a week to let it rest. Best of luck with this. Cheers Gleniveve