Complex sentence: For much of the series, she also lived with a stepmother, named Gloria (unseen character), who is often referred to as "the stepmonster" due to her mood swings and various addictive pills.
Split into simpler sentences: For much of the series, she also lived with a stepmother, named Gloria. She was often referred to as "the stepmonster" unseen character due to her mood swings and various addictive pills.