のは私よ

It was me who…

→ の
phrase Rare #45,323
It was me who… Follows a clause to emphasize that the speaker was the one who did the action; よ adds emphasis in a conversational tone.
JA: ドアをノックしたのは私よ。
EN: I was the one who knocked on the door.

ドアをノックしたのは私よ。

I’m the one who knocked on the door.

あなた達は命令に従っただけ置き去りにしたのは私よ

You were only following orders. I’m the one who left them behind.

— オデッセイ (2015)

「彼を水から引き上げたのは私よ」と言った。

“I was the one who pulled him out of the water,” she said.