What a mistake she made. Do you really want to be the one to 'fix' her problem? Is she that good a friend or customer? She would pay you to 'fix' this wouldn't she?
Hopefully she would find material to use - why use up your time unless you really want to. An underskirt or I forget the actual name, but another quilted item to be put under the original quilt [can be store bought], pleated under skirt, ruffled underskirt.
She could also call it a large throw, or if it is King sized a very large throw. Not all my blankets were as long as I wanted but they did keep the bed warm at nite.