The Villainess Duke Lady Hides Her Identity

I was the perfect spy raised by the Pope.
To infiltrate the Kreitan Duchy and steal their heirloom, I took a potion to shrink my body.
“Why are my hands so small? What’s with my voice? Ah! My pronunciation! Why am I so short?”
But something went wrong, and I turned into a five-year-old child.
If I failed the mission, only death awaited me. To survive, I tried to do something, anything, with this five-year-old body.
“Lephonia Kreitan. From today, you will be my daughter.”
I was adopted as the youngest daughter of the Duchy. If this is also infiltration, then so be it…
***
It seems the Duke adopted me as a substitute for his lost daughter.
Fine! I was planning to use them to find the heirloom anyway!
Since it turned out like this, I’ll enjoy the Duchy properly before I get disowned.
That’s what I thought…
“Phonia. From now on, even the smallest injury must be treated. That’s the family rule.”
“Cotton ball, you can tear the curtains with scissors and no one will say anything. This is your home, isn’t it?”
“Phonia. My little sister. I’ll give everything our youngest wants for the rest of her life. You just need to smile, our youngest.”
Why are these people so good to me, even though we’re not related by blood?
I only infiltrated through adoption for the mission.
I shouldn’t have any useless expectations, and I should run away.
“Where do you think you’re going after taming me? Who cares what your real identity is, Lady?”
“……”
“Just take me with you. I’ll follow you anywhere.”
My feet keep refusing to move.
Am I allowed to be greedy on this?