My criteria for baby quilts is much different than for bed/gift/occasion quilts. Baby quilts get a lot of wear and tear, and babies/kids aren’t usually particular about pattern. So for baby quilts I do something that looks nice but isn’t too intricate. Since you have a focus fabric and you say you want 6” blocks, I’d recommend Warm Wishes. Your focus fabric will be cut in 6.5” squares, and you can strip piece the alternate blocks with 2.5” strips. It will go together fast, showcase your focus fabric, and look good finished. You could also alternate plain squares with 4-patches, or do a 9P and Snowball quilt.