Casting<em>web </em>is an action. That would take Corinne's action for the round, and preclude also actively helping.<br/><br/>Zoe is able to help. Corinne could spend her action casting<em>web, </em>and also encourage Zoe to help Sage out of the cabin pit. If you want to do that, you should make the Athletics DC 12 check for Zoe. Her bonus is +0, and there's no disadvantage as long as she does only the one thing.