The Villainess Duke Lady Hides Her Identity

I was the Pope’s perfect operative.
To execute my mission—stealing the treasured heirloom of the Kraytan Duchy—I drank a shrinking potion to slip inside unnoticed.
“Why are my hands so tiny?! What’s with my voice?! Argh, my pronunciation! Why am I so short?!”
Something went horribly wrong, and I regressed into a five-year-old child.
Failure meant death.
I was ready to do whatever it took to survive in a toddler’s body, but then—
“Leponya Kraytan. From this day forward, she is my daughter.”
I ended up adopted as the Duke’s youngest child.
*Fine by me! I was planning to use them to find the heirloom anyway!*
*Since it came to this, I might as well enjoy the high life before they disown me.*
Or so I thought…
Why is this family treating me with so much love when we don’t share a drop of blood?
This adoption was just a cover for an infiltration.
I know I should cut ties and run before I start building up useless expectations.
Yet, I can’t seem to take a single step away.
Would it be so wrong of me to wish for this warmth to be real?