a taxidermist can help you...or should be able to. You will have to just pick a size that well represents her catch, as best as you can.
I have a couple unpainted replica black crappie in my shop you can come look at to get you started in your quest if you like. I am not far from ya at exit 47 on 840 and you dont even have to let me do it for ya. I think I have a 15, 17 and 18. Should help you get and ideal of what to order.