Wow. How upsetting. I wish you the best.

Some material just does that...I have a quillow that does that in a new place each time I wash it. I would make my seams .5" next time.

roguequilter is correct - prewash flannel and use the bigger seam allowance. Like you, I learned the hard way.

I prewash everything especially denim and flannel of any quality and my first quilt was a small denim for a doggie bed. my neighbor told me to use at least 1/2" SA. and zig zag it. that was more than 10 years ago and it's still intact at the seams. A little worn in other areas but in tact at the seams.

When sewing flannel, you need to use a 1/2" inch seam instead of our usual 1/4" seam. If you did this, then I am sorry I have no answer.

you probably should add wider strips now to cover more fabric. make it a design change!!

oooooh.......I like nativetexan's idea.......add (topstitch) a new and wider sashing overtop of the old one. Then I would also add more quilting, like an "X", a heart, or a star in each block. If you like hand stitching, a long stitch in red pearl cotton would look homey and cozy with that quilt.

Sorry for your trouble. I just spent 4 hours this morning recovering from a mistake I made. It happens to all of us. Good Luck.....Jane

Flannel requires at least a 1/2 seam to keep that from happening. Shorter stitch length helps too.

OMG, your beautiful quilt! Sounds like you've received lots of good advice already just wanted to send positive thoughts.
I always prewash everything, even precuts, in the sink, salad spinner to get them dryish, then lay them on the counter to dry. Not much help at this point!

Oh no!!! I sure feel bad for you. It may have been that you took too small of a stitch seam?? That is so disheartening and I bet you just about wanted to throw up your hands. Hopefully it can be repaired and no one will ever know. Sure glad you washed it before giving it. Good luck.