The reason she married when she was 7 months is because of her mother’s death and Kong’s trying to protect her and revenge duke ! Duke had a lover and when he married MC’s mother , he already had 5 children with mistress and ignored his wife.
Mc’s mom died while giving birth to MC and at that time duke refused to come to her side bc he was out with his mistress partying their child’s birthday!
Few months after her death he married the mistress and made her duchess. And now Mc is the heir of their land cuz new duchess is too old to give birth to a new an legitimate child.
Well it’s a long heartbreaking past
You can read the novel for free by simply googling its name
Wow I just read its novel! It’s wayy darker than the this fluffy manga! Ugh I hate duke and I want to rip his thing off! And I his bitch even more