Complex sentence: She befriends the young Bruce Wayne, who is immediately smitten with her; unbeknownst to him, Silver is helping Galavan in his plan to kill Bruce and take over Wayne Enterprises.
Split into simpler sentences: She befriends the young Bruce Wayne, who is immediately smitten with her. Unbeknownst to him, Silver is helping Galavan in his plan to kill Bruce and take over Wayne Enterprises.