Complex sentence: Katsutaka Anjou's wife and possibly the only one trying to help Yousuke figure out who his sister is but at the same time preventing it by hiding importing information as she appears to enjoy the adventures the children have trying to find out.
Split into simpler sentences: Katsutaka Anjou's wife and possibly the only one trying to help Yousuke figure out who his sister is. However, she at the same time is also preventing the discovery by hiding important information as she appears to enjoy watching the children trying to find out.