The thing that I find that works really well is to select the fabric with the receipent and then they really look foward to it and appreciate it. I am now sending a quilt to a girl friend. we selected the pattern and the fabric together. She cannot wait to see the finished product. We made the selections two years ago ......I have several other jobs.
It is still a surprise because the finished quilt is greater than the selected fabrics. The process created a sense of ownership that leads to appreciation and folks recognized that it is especially for them...
So maybe when your sister in law comes you can select the pattern and fabric with her.