>>There had better be a chance to tenderize her parents somewhere in the campaign.
If you go down far enough into any dungeon they all connect to the Underdark. Yes, even the the old castle basement you cleared out at first level. It was behind a secret door. They all connect and word spreads.
OP's parent's were the Avengers, John Steed and Emma Peel. Or James Bond and Ellen Ripley. Two hardcore badasses. They toppled kingdoms and the ramifications of their delvings are still being dealt with on multiple plains of existence.
Are you going to be the one to mess with their kid? Admittedly most of the aunties and uncles that she was dropped with had only a vague inkling, but they knew that this was a child with some strong ju-ju. Hence her exposure to dungeon culture, which was mostly old hat to her, she was picking locks at age five.
Surface dwellers think of all beneath their feet as horrible beings, but monsters have families. Cruel families to be sure, but it is a cruel environment. Foundlings from the surface being adopted below are not unknown. They rarely survive the harsh environment, but native mortality rates are high as well. OP's character however was trained from birth and saw the tests of survival as fun games that reminded her of how her absent parents used to play with her.
To tie back to the original quote, the parents sort of knew that their kid wouldn't be killed outright and were confident she could handle a few days (ok, months, that last quest took awhile) in dungeon daycare.
>>They need to have some sense beaten into them, plus it'd be an interesting encounter.
Oh you meant that? Beating up a senior citizen who OP's character adores? Bad form.