Check out this place http://www.ski-esprit.co.uk/. The ski school I worked for in Austria did a lot of work with these guys and they did a very good job of providing budget ski holidays for families. The Snow Rangers are available to look after and entertain children of all ages from the moment they wake up in the morning till you get back from the pub in the evening. It looks like the only Swiss chalet they have is in Saas Fee. But probably worth a look, and Austria may possibly be cheaper for a family.