Shi shi beach and Point of Arches, easy and beautiful(I shopped in the bear but the sunset is normal). Hurricane Ridge is mobbed, sometimes you can't even park. Dosewallops Falls is great, the road is washed out so you can hike into old drive in camps.

If the step-daughters are out of shape, overweight, etc., good luck with that.

Be prepared for rain.

Always take plenty of water, and always know exactly where you are. If there's a sign-in at the head of the trail, or at a ranger station, use it. As for getting kids to go; maybe start with taking their phones away?