This has happened to all of us at one time or another
. Step back take a deep breath and close your eyes. What was it about the layer cake that you liked? The colors, print, how it went together, it reminded you of your mom, it reminded you of something from your past? All good questions and something you should think about, you'll have your answer. If none of it applies because you just liked it, then you will have to use it in something else at a later date. Back to the layer cake and your embroidered designs, if you place your designs down the middle of your quilt (like a panel). You could do a boarder or two in a solids. Or do a narrow boarder in a solid, perches a little yardage from your favorite print from the layer cake (just one print). Then make a little wider boarder using this print, then one more boarder in a solid. Now you should be able to use your layer cake all around this new panel you have made. I hope you find something you will be happy with, I'm sure you're being too hard on your self. Your mother will love your gift, because you made it and gave it to her.