Ace just observed Elise and Ace, knowing even if he wanted to help Link, he knew as well as Elise he was in no condition to fight at the moment. Plus, she was showing no hostility to Ace, so he had no reason to start conflict. Ace lived as a loner most of his life, so he wasn't the one to risk himself over another. "Well, Link did try to steal you out of a meal before," Ace had people do recon before he got here, so he would have knowledge of the area.