In reply to Thelittlesthobo:
Chapel Stile was pretty good with the sprogs.
Alternatively, would some wet scrambling be a good bet for later in the year. Our kids are/were totally ambivalent about climbing. They enjoyed trips to 'bleau but not much enthusiasm for other formal climbing.
But over the last few years we've done a few scrambles and they absolutely love it. Like properly love it. Last Whitsun was a glorious succession of lovely watery beck scrambles culminating in the Upper Esk Gorge.
Swim across a pool, climb a short waterfall without a rope, fall in, laugh, swim, climb it again (properly), traverse across another crystal clear pool, fall in, swim, climb a lovely clean rocky buttress, picnic lunch, climb waterfall using a rope, climb buttress next to waterfall with rope, another amazing pool etc