Thanks for the chapter!
LN explains better but what MC was referring to about the clan in association to the driver was about the infighting for position where even death was a favored option as long as there was no evidence. Although in this case the assassin was probably sent by daddy dearest in hopes of having the favorite daughter marry the prince for power and prestige. That and considering how much honor and face were prized in those times the assassination was likely to cover up how badly the clan was treating the Prince's fiance, and being a prince would mean that unless the Emperor stopped him he could murder the whole clan for the implied insult, intended or not. The old nurse was likely sent to make MC and family lower their guard and get in the carriage as a sign of good faith whose corpse would be lying in a shallow grave next to theirs. Going to be interesting to see how daddy dearest reacts to them showing up alive and whether did everything himself or had accomplices.
Btw, is it common for boys that age to have those hairbuns, thought only girls went for that look?