Ok, here's what we've got so far I guess:
He takes her with him, in hopes to redeem her and turn to the light. She is somewhere around:
(pick two different)
So they travel together and he does what he always does (helping, smiting, behaving) and does his best to don't let her do anything evil.
She eventually sees that gratitude is something heartwarming and worth fighting for. That trust is something not found among chaotic evil dickfaces. That true love that she feels can't be anything but good.
So she snaps, grows out of shenanigans and turns to the light side, maybe not instantly, but inevitably. While obviously NOT being liked by other people, paladin protects her from xenohating ignorants, because DURR, he's a white knight.
So she eventually becomes if not lawful, then at least neutral good. And to be even closer, to understand paladin better, she becomes a cleric of his deity.
Afterwards they don't argue much and live a happy smiting life, purging undead and helping old people with dangerous tasks, earning delicious rewards.