Welcome!
And that looks very much like 2-1/2" strips with 4-1/2" strips and maybe a few 3-1/2" strips. It looks like they did the wider strips mostly out of the light and medium tone fabric and used mostly the distinct prints and darker colors for the narrow strips. Although the plaid seems to have been used in both wide and narrow strips.
To do with your daughter's fabric choices, fold the fabrics and lay them out on top of each other so that the strips are the width you are thinking of using and the order you are considering, then play around with rearranging it till you are happy with it.
Have fun!