There is no measuring stick with which to measure traits. It is true, that everyone has strengths and weaknesses that come naturally but true strength is in recognizing what we do well and how to supplement what we feel we struggle with.
Years ago, I worked in the printing industry and it was my job to design things for customers, even logos for new local businesses. People often commented on how creative I was, but as a non-artist, I knew that I had learned some basic principles of design which served me well.
We can admire others as creative and find ourselves lacking, or we can recognize our own strengths and take what we need from other sources. Put away your measuring stick and be happy that you will love the design of your new quilt. You chose the fabrics and generated the original idea, it is not your sister's quilt.