The Argents are a family of gods who primarily preside over various aspects of war and the forge. Allison is young (you know, by immortal standards), but she becomes relatively important in the pantheon quickly, once it’s discovered she’s a goddess of war and justice (amoung other things; she’s really an amalgamation of Athena and Artemis).
She wasn’t around when the Hales were still alive/free, so from the start she’s been told tales of horrible wolves that would eat both mortal and immortal alike, but Kate had swooped in and saved them all by getting rid of them! So from the start, Allison hasn’t been a fan of any of the remaining Hales at all and she thought Kate was a hero.
Scott knew of Allison before he and Stiles freed Derek, mostly from Stiles sneaking them into big gatherings of gods so they could spy on them and be ridiculous. He never approached her before, until after he gets dragged kicking and screaming into the mythological clusterfuck. And, well, you know how it goes. She loves him in spite of his furry problem, has conflicted loyalties between Scott and her family, etc, etc.