Welcome! If you think that 6" is too wide, you can always put a small border first and then the 6". If you choose to put a smaller border first though, I'd make it the same width as your log cabin strips. And if you still think 6" is too wide, make it 5". Your quilt is quite pretty, so whatever you do will only enhance the charm and beauty of what you have already. Please, post a photo when you've finished.
