Complex sentence: After her parents failed to betroth her, her family was convinced by an "unfavorable horoscope" that she was bad luck, her father's employer, Gertrude Howe, adopted her.
Split into simpler sentences: After her parents failed to betroth her, her family was convinced by an "unfavorable horoscope" that she was bad luck, she was given up for adoption. Her father's employer, Gertrude Howe, adopted her.