After Traveling Back from a World Where My Physical Fitness Had Increased a Hundredfold While I Remained Unchanged, My Whole Family Was Dumbfounded

As the real heiress who was switched at birth, I just returned from a world where everyone else's physique was a hundred times stronger while mine remained unchanged. I immediately ran into the Prime Minister's nanny, who came to take me back. Her first reaction upon seeing me was shock: "This... This is fourteen years old?" But seeing my striking resemblance to the Prime Minister's wife, the nanny reluctantly took me home. Back home, the fake heiress claimed to be frail and sickly, asking me to be lenient with her. I immediately accused her of lying. I've never been crushed by clothes, so what right do I have to claim to be frail and sickly? The fake heiress didn't believe me, so I threw the clothes at her.