Muse, your block for Marija is so pretty. I love those grayish greens with her print.
Marija, it's best if you stick with the 12.5" size, so the bonus blocks can be used with the other blocks. Of course, they are not a requirement, just something extra out of the goodness of your heart... So, that being said, you can do anything you want for an extra. (Or no extra.) They just will be harder to use with the others if they are a different size.