She grew up among humans or other elves, in a rather isolated sect of sun-worshipers. Though unable to truly embrace the glory of her deity (given her racial hyper-sensitivity to sunlight), she hopes to one day redeem her entire obviously-evil race (and thus herself), allowing them to step into glorious day without fear or suffering.
Which is all bullcrap, of course... she was STOLEN as an infant and raised in sun-worship as a cruel joke by zealots, who wanted to turn one of their enemy into a weapon against her own kind.
She's a pure sweet cinnamon roll who truly believes in the divine redemptive powers of the light, and also that she is a horrible sinner whom must atone, alone, for the entirety of all the darkest deeds of her entire race as well.
Now starting to plot out a drow paladin of a sun god. One I'd done some work on before, but now coming back to the concept...