The Grand Duke’s Little Lady

Ariel was born in the Marquis family but she was abused and abandoned by them. She ended up a miserable death filled with endless misfortune. When she woke up, she was nine years old again. In order to not repeat the miserable life, Ariel decides to have a contractual marriage with the son of the grand duke, Lakatyer, who is famous for blood and madness.
“Good, Ariel. Now you are the Lady of this house.”
“But I just married yesterday…”
“The Grand Duchess is not here so you are the Lady of this house.”
Ariel responds, clenching her fists, “I will do my best.”
“No, you don’t need to do your best. The house is all yours. So just think of how to enjoy it.”
Why is everyone so nice to me?
“Speaking of which, what are all these keys?”
The housekeeper glanced at the keys and laughed.
“These keys are for the treasury of the grand duke’s family.” Yeah? What do you…?
‘He said that I can use all of them as I please because there are all mine?’
Ariel just barely understood the situation barely and surprised. Wait… it means he left all his treasures to me even though I’m just ten years old? She was confused, why does she have the repository keys of this house? Will the house be fine with this?
The Grand Duke’s Little Lady / 대공가의 아기 마님