Fl's sister's lover was the Crown Prince, Ml and the crown prince are cousin. But Ml's father relinquished his right to the throne. Hence why the blond hair and blue eyes that are royal traits.
Cp was murderd hence the sister keept her child a secret and fl ran away after the one-night stand because her sister came home that night covered in dirt and blood and covering in fear.
Fl and her sister left the county and then learned the sister was pregnant, Fl feared herself being pregnant but was relived when found not to be. Fl had her hands full hiding her sister who was almost assassinated along with the Cp.
Do not abbreviate crown prince i just had a heart attack
Didn't it said that she have a one night stand with ml. It weird how her sister is pregnant and have a child that kind of look like ml, and not fl while she the one who slept with ml.