At this point at 1 yr old, go simple.
Take a 12X 24" piece of fabric and embellish half of it how you like - embroidery, applique, quilting, whatever.
Sew up the sides. Fold over the top edge, and add a strap.
She's going to drag it through the mud anyway.
When she starts school you can make her a 'special' backpak.