Everyone has their strengths and weaknesses. I piece very well, enjoy basting and hand-stitching the binding. I am good at choosing complementary colors and fabrics. I have a very hard time, however, choosing a pattern/design and especially deciding how to quilt the basted sandwich. That is why I SID for most of my quilts. I spend SO much time looking here and googling to get FMQ ideas and still, I have a hard time. Using your sister's idea, to me, would be no different than using someone else's pattern or, in my case, using an idea from here or the internet for FMQ. You are still the one doing the work so revel in your accomplishment and all the praises you will get!!