South Node symbolizes the things or people from the past including past lives for those who believe in it.
Ann Marie suddenly remembered someone who got in touch with her months ago with some potential money making opportunity. Ann Marie wrote back to that person who then replied. And yes, that person is a woman, as symbolized by the Moon.
As Ann Marie’s South Node is her 8th house, I wonder whether the woman whom she was in touch with interacts with magic and the occult – which I suspect she does.