You are creative enough to be making quilts. I think your sister's suggestions were meant in a kind way. Just because she shared her ideas does not mean you have to change from what you were planning. When she makes her quilts they will be her way. Make yours your way. If you like her idea, you can always make another one her way later if you want to.
My sister and I were complete opposites and we both made pretty quilts our way that our family loved.