знаком с ней

be acquainted with her

→ знакомый
phrase Uncommon #22,234
be acquainted with her Used for meeting someone or knowing them personally. More formal than just "know her."
RU: Я знаком с ней уже несколько лет.
EN: I have been acquainted with her for several years.

Но если я её даже не знаком с ней?

But what if I don't even know her?

— Почтальон (1994)

Ты знаком с ней?

Do you know her?