Don't be so hard on yourself. I bet they want even notice. However you do have some good options that was stated above.

A cotton batting that shrinks a bit will hide both piecing and quilting irregularities after it's washed. Puckering is your friend.

Thank you all for the tips and the reassurance! I feel less apprehensive now.

Ha ha...puckering is your friend! I like that and it's so true. My Quilts for Kids was also a little off, but I sent it anyway. I didn't even take a picture of it. The child will still love it!!!

Once it's washed, you probably won't even notice. If it's that far off, maybe applique something over that spot. It can look intended, not like a coverup.

Unroll a few different color threads and see what looks good to you. I love variegated thread. I have a pretty yellow variegated that I've used on a few different quilts. If you are uncomfortable with FMQ, blending the thread to the fabric will help hide mistakes too. I often use a serpentine stitch instead of stitch in the ditch. It's much more forgiving when I can't stay in the ditch. :)

I've used a decorative stitch over some "unmatched points". Maybe that will help.