Hi missykiwi, how old is your child? My daughter used to be really cranky in showers due to fear of water getting in her face /eyes too, so I started to play with her in the shower while getting her to look upwards. This is so that when you wash her hair with showerhead / scoop of water etc, it runs down the back of her head instead of her face.
If she is old enough to know facial features, you can ask her to look up at you and point out your nose, eyes etc while you quickly wash her hair. I also ask my little girl to spot shapes like circles, squares, rectangles if there are any shapes in the bathroom that she has to look up at, like the round spot lights for example. This has worked for me, and after some time she no longer fears washing her hair.