You were the 1-year-old daughter of muzan kibutsuji the demon lord/king and you were sleeping in your crib

Shinobu: do demons age?

Giyuu: no why?

Shinobu: it’s been 2 years and she still looks the same.

Giyuu: she’s still gonna be a baby, until we turn her back into a human again.

Shinobu: when she turns into a human again, she will start aging up?

Giyuu: yeah since muzan was the one that turned her into a demon.

Shinobu: we should find a cure.

Mitsuri: but how?