Great job on the quilt. I have one to make that I have been avoiding. I may have to steal your ideas just to get started.
For the quilting, I love W&N because you have a 10" quilting area. That's a very big area to leave open. (I don't usually leave that much open, but it's oh, so nice to know I can.) Then I would outline the blocks (just to stabilize everything), do something in the sashings, then a close pebbling or meandering or wiggly line in the tee shirt areas themselves, making every effort not to go over the writings. Just some straight lines in & back out would work in some of the blocks. Making like sideways U's. Or a loopy that crosses over each other on the way in or out. Write her name out in the area under Oklahoma, and any other info that you'd love for her to see every time she uses the quilt. On that Sooner tee, you could do an echo quilting in each corner to emphasis the central design. I'd look at each quilt block to see what I wanted to do.
I haven't tried the idea of drawing the design out on a clear paper, think dry cleaner bags, or some type of rolled wrap, but that would probably work very well to make up unique designs for all these blocks. I can't wait to see how the quilt after you get the quilting done and bound. It's really going to be something else!!!
Just curious....what did you back the tee's with to stabilize them for the quilt?