Wow. Great to hear from you. I am usually skeptical about whether I have a match on here, but your "white knight" comment almost has me sold.
Indeed, the story from our family goes that Marianna came from a well-to-do family in Amioun. Her father had an olive oil business that did well, then not, then well again. Around WWI the family business went bust. Marianna fell in love with a poor man from Beirut by the name of Elias Nassar. Marianna's father was not happy about Elias' socio-economic status, so he forbade her from seeing him. She nevertheless mArried him, and was consequently divested of the family estate. After WWI, and a child dying from malnutrition,they planned to escape to America. One day Elias rode into Amioun on a white Arabian horse to take her to the port, where they were to embark on a journey to America. They succeeded. Marianna's family disowned her, and tried to have Elias arrested and extradited for kidnapping her.
Elias and Marianna settled in the Pittsburgh area (Clariton, PA). They had many children, one of them being Gabriel Nassar, my grandfather. I believe both her and Elias were born in 1894. She died I. 1997, at the young age of 103. One of my fondest memories of her is gong to her house and helping her till her garden.
I know I'm biased because she is my great-grandmother, but she was the sweetest old ladie I've ever met.
Let me know if this information matches what you know about "sitto."