Madeline had her own reasons for deciding to propose a marriage to the young lad. She wasn't deaf when the Coachman referred to the young man as Lord Cassian, for she knew of only one popular man bearing such a name in the upper East quarters.
Lord Cassian, the son of Duke Richard himself.
Lord Cassian was known to be quite a charmer with a commendable physique, and it certainly wasn't a fake rumor since she's standing before him and taking notice of his appearance herself.
Not everyone is lucky to physically run into Lord Cassian~ scratch that, what she meant to say was, not everyone can be unfortunate enough to run into Lord Cassian. It was difficult to interact with a man who was fond of steering trouble towards his direction.
He doesn't associate with people, and If he does, it was either to kill them, or send them behind bars for committing something. This explains why most people are fortunate enough to stay clear of him.