As a starter drive through Windermere,(town, not Lake), Troutbeck Bridge, Ambleside, Skelwith Bridge and into Great Langdale Valley. Go to the end to Old Dungeon Ghyll.
https://www.google.co.uk/maps/ at 54.3792818,-2.9022916,11.75z
https://www.google.co.uk/maps/ at 54.445687,-3.0950129,15z
You can come back the same way, or go up the hill and come back via Little Langdale Valley.
The trip over Kirkstone pass into Patterdale is impressive, particularly this time of year. The Kirkstone Pass Inn is an evocative watering hole; and you'll be very welcome in Glenridding after the floods. Trade is seriously down in the Lakes apparently.
Another nice pretty spot is Tarn Hows, the other side of Windermere; just beyond Beatrix Potter's house at Far Sawrey. Accessible for youngsters.
My personal favourite is Derwentwater. Great views from the road to Watendlath.
Personally I would try to stay closer to the lake district itself or actually in it, somewhere like Keswick or Coniston. plenty of place to go and see around those both driving and walking, I know you said about not walking but there are plenty of lakeshore and lowland paths to stroll along to get you out of the car.
------------- Why have kids when you can have a dog?
From Kendal it's not far to Bowness - really touristy but a nice (short ) walk along the lake shore, go left along The Glebe as you look at the lake where the steamers go from. You can also get the ferry across the lake as a foot passenger (50p each way) or with bikes and have a short walk/ride on the other side. Best place to park for this is the Ferry Nab car park. Plenty of opportunities for boat trips on the lake, either oar or motor powered or on one of the steamers. There's a steam railway at Haverthwaite that connects with the Windermere cruise boat at Lakeside, if you like that sort of thing. You can drive to Tarn Hows near Coniston for a walk round all (about 4 miles?) or part of the lake, or go to Ambleside for the short waterfall walk. Plenty of good "watering holes" in Coniston and Ambleside, incidentally. Between Bowness and Ambleside, a good day out with children is the National Park Centre at Brockhole - lots of space for running around, playgrounds and at the edge of the lake, and they often have special events. No entrance charge, you just pay for parking. The cafe and shop are not cheap though! There's a book of Lake District walks with children, designed to allow children to lead the walks, though I can't remember the exact title. Sure you could find it if you Google it though. At the bottom end of Lake Windermere is Fell Foot park (National Trust), lots of grassy space and lake access, and on the same road is the turning off to Gummers How, a short but steepish walk up the hill, giving good lake views. At Lakeside there's the Lakes Aquarium, handy for when it rains! Grizedale Forest is a little further to the south but worth a visit, with lots of forest paths and trails of varying lengths and a playground, visitors' centre etc. Also free except for car parking. Hope some of these ideas are helpful.
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.
Topic: The Lake District
