Complex sentence: She is aware that she is beautiful and that Arthur is in love with her and enjoys using her attractiveness to taunt the boy however when one of her games goes too far and Arthur is nearly killed she is wracked with guilt.
Split into simpler sentences: She is aware that she is beautiful and that Arthur is in love with her and enjoys using her attractiveness to taunt the boy. However, when one of her games goes too far and Arthur is nearly killed, she is wracked with guilt.