She only knew about the kidnap plot, but she didn't know about the murder plot. Based on what I read it says that, it is possible that she knew about the kidnap plot, but that would have determined a less harsh punishment than death. This proves that, she knew about the kidnap plot, which means she was guilty, but she wasn't guilty by death.( Article 2)
According to the text it says that, she was innocent and only trying to jind John Northy, who owed her money. This indicates that, she had no idea of the kill plot, but just wanted to get some money back. (Article 2) She was only guilty by association, and she didn't do any harm to