She has character growth, but it's mostly from "spoiled brat" to "manipulative shrew, who then bats her eyelashes so people still like her."
It happens even in the last book of Belgariad- when she's with 'Zakath, she flashes her "little girl smile" (that's a quote) when she annoys him, so he won't get angry.
And in her last scene of the series, she gets into an argument with Garion, purposefully twists his words, and when he objects she legitimately says "Don't you love me anymore?" This is followed by Garion thinking about how he knows she's manipulating him, but he can't help it.