I’m surprised by your comments on Whinlatter Blue. My nephew did this recently on a wooden push along balance bike and he’s 3 years old. The only problem was fatigue near the end. It’s such a great route too, I’d stick with it. The south loop of the red isn’t much harder really.
Otherwise, Sherwood Pines has Green, very easy blue and very do-able red routes – my nine year old manages the red route just fine and is very new to all this.
Dalby has similar but the red gets far more tricky.
Avoid Gisburn IMHO.
Do you lead from the front or follow behind your children?
I was following behind and being probably too over the top with the amount of verbal encouragement and praise I was giving. Whinlatter blue took about an hour and ten minutes. I now lead from the front and have cut way back on the amount of talking/praising I do . We did it in 50 minutes last time round and he enjoyed it much more.
Hope some of that helps.