Quiraing is a top suggestion. Stunning place and the kids should be fine there.

If you get nice weather, park by the Sligachan Inn and let the kids play in the burn for a couple of hours while you enjoy the finest views anywhere.

Another one very much worth doing is to drive over to Kylerhea and head on down to the "otter hide". It's less than a mile on an easy forestry track, which my 3 year old biked along. You then arrive at a stunning wee hide where, if you stay a while, all sorts of wildlife will become apparent. On our trip there last month, we saw cormorants, seals, an otter, lots of other birds and an eagle!

As for the stop off, of course Glencoe is a great place, but be aware that the weather can be "interesting" because of the proximity of the mountains. Which way are you heading to Skye? The RET makes the Mallaig ferry very affordable and great fun....but be warned, you DO need to book. If you do go that way, and depending on how much you like to get back to nature, go and stay at Rubha Phoil, on the peninsula as soon as you get off the ferry. I think they're planning to get the camping areas open shortly, or there is a wigwam as well. The camping spots are stunning.