If you get a crap wet day, there's a soft play in Ambleside - sorry not sure of the name of the place - it's a large restaurant/cafe with a soft play area that's quite good. Think it might be Piano Bar or something to do with a Piano anyway!
We went to the Lakes in the Summer and I posted here before we went and got loads of suggestions from lovely MNers! I printed off the thread and took it with us. Hope you have as good a time as we did.
Thank you all so much - i have printed off your old thread as you suggested martha as well as these suggestions.There are so many tourist attactions in the Lakes - its hard to know which ones will be suitable (and value for money )for a 5yo. As always, MNers are such a resource