Hello, looking for any series where an older person either 'adopts' a kid or marries someone with a kid. And then the kid grows up and falls in love with the step parent.

examples:
I Became the Villain's Mother
Picked up a little fox

Usagi Drop... can't think of any more!

Don't mind if it's guyxguy or girlxgirl

A Stepmother's Märchen widowed stepmother.
Suna no Shiro female lead adopts former lover's child. Highly recommended for a feels trip.
Antique Romance a girl got sold to an older guy. Kinda related since he treated her like a child before romance ensures (I think).

I know a couple of smut that also fits the bill, but idk if I should recommend (personally the ones I have in mind are the ones I'm not a fan of).

I'm in idol hell T.T

If It's for My Daughter, I'd Even Defeat a Demon Lord but it's based on a light novel series.
Actually, I'm not sure how far the manga is right now or if it'll cover the entire story so it might be spoilers but there is romance when the girl grows up in the novels.

Edit: Remembered another one, which is yuri: Hoshikawa Ginza Yonchoume