I've never met her before.

never Adverb

— If something never happens, it does not happen at any time. As a child I was told that I should never tell a lie.

met verb

— (obsolete) To dream.

Met properNoun

— (London) The London Underground Metropolitan Line — (London, historical) The Metropolitan Railway — (London, law enforcement, usually with "the") The Metropolitan Police Service of London (MPS) — (US, with "the") The Metropolitan Museum of Art in New York City. — (New York, arts, with "the") The current or historical Metropolitan Opera House or its opera company.

Met noun

— (London, informal) A Metropolitan Line train — (baseball) A player for the New York Mets

her Pronoun

— You use her instead of the name of a person, to talk about a woman or girl. (used in the object or complement position, never as a subject) This is Susan's book. Give it to her. — If you say something is her thing, you mean it belongs to a particular woman or girl. It is her book, not mine,

before Preposition

— If mathx/math happens before mathy/math, mathx/math happens first and mathy/math happens second. He worked in a gas station before he became famous. Put out the fire before the house burns down. I have not been there before. She finished before me. — in front of something She stood before him, looking into his eyes. — until It took a few moments before I realized that she was joking.