Just beautiful. I haven't done one of these yet but I have seen a lot of them and yours is beautiful. I look forward to you posting a picture of the finished quilt. I'm sure your sister will be thrilled.
O a funnier note, I had to chuckle when you mentioned something about thighs and plastic lawn chairs. My husband keeps a few of those outside his workshop and one collapsed a few weeks ago when one of his friends visited. He didn't get hurt thank goodness and they had a good laugh about it.