Great-Grandma in Chief

Sophia is in her twenties and, once her parents are counted, nobody in the family outranks her. Generations below her include people in their eighties, and by the rules of the family tree they address her as Great-Grandma, which they do. She trains as a pilot and takes a job at the airline the family owns, where none of that seniority means anything to the people she works with. A colleague there sees her with someone and concludes she is a mistress being kept, and starts treating her accordingly. Sophia has spent her life being deferred to by men four times her age and has no intention of letting the assumption stand.