Complex sentence: Riki-Oh and Nachi's biological mother, she was executed by hanging for poisoning thirteen infants 25 years ago, before her death sentence, with help from a friend of hers, Riki and Nachi managed to escaped from prison.
Split into simpler sentences: Riki-Oh and Nachi's biological mother, she was executed by hanging for allegedly poisoning thirteen infants twenty-five years ago. Before her death sentence, with help from a friend, Riki and Nachi managed to escaped from prison.