Here's a D9P that I recently made for one of my granddaughters. I did use 2 differenct fabrics for the center of my 9 patches, you would be using the same fabric for your centers to keep it a 3 fabric quilt. May in Jersey

I agree with those who suggested a Rail Fence pattern, which is easy to make and uses the same amount of fabric in each block. I'm attaching pictures of a Rail Fence top that I've completed except for adding the borders. If I were doing it over, I'd switch places with the pink and the white w/rose print. I took the pictures at night and the colors don't show as bright as they really are.