стоило ей

as soon as she

→ стоить
phrase Rare #25,871
as soon as she In the construction стоило ей + infinitive, как ..., it means “as soon as she ...”; the construction often suggests that the second event happened immediately afterward.
RU: Стоило ей открыть дверь, как зазвонил телефон.
EN: As soon as she opened the door, the phone rang.

Стоило ей прийти, как она снова ушла.

As soon as she arrived, she left again.

Стоило ей погладить щенка, он умирал.

As soon as she petted a puppy, it would die.

— Ночной дозор (2004)