Just calmly say "yes, Mother". Any time and anything, just say "yes, Mother". If it comes back, don't be a snot--"yes Mother. Its hard to argue etc with someone who is agreeing with them. Hopefully eventually she will get the message. Ignore her criticisms and do it your way. Be the bigger person and just ignore what she complains about, many people still tie their quilts. Bringing backing over to the front is a perfectly acceptable way to finish. Besides they are your quilts, and I suspect she may be jealous because yours are actually better than hers. Just hang in there, be positive and ignore the complaints. I suspect she senses she is loosing power over you and resents that.