hi
I went to Aveda in the centre of town, not far from Marktplatz where some of the staff spoke English. It's expensive, BUT it looked good at the end. We too have two kids and took them into a salon near where we live where they didn't speak English, nor us German and oh my WHAT a mistake!!! Have a look at their website, I'm sure they do something on a Wednesday if you have your hair done, the kids get done as well for free?
http://www.pureaveda.ch/index.cfm?pageID=37