All good advice.....
I would vote for take your time and quilt straight lines (with a waklking foot if you have one)... you can still quilt straight lines without one tho..... Quilt straight lines 2 inches or so apart in a grid, either horizontally and vertically or diagonally... Take your time. It would help hold the layers together and if she loves it... its a *live and learn* experience.. .and she will still love it.
Make some creative sew or iron on patches to add now and then later, (besides the straight line quilting).....
And, belatedly, its one reason why people prewash their fabrics... but I wouild still quilt it and let it be used... (sheeps)