I think it's absolutely intentional. It feels like it's written by and targetted towards people who are viscerally repulsed by pedophilia.
It's creating a situation that feels like absolute horror, and using that revulsion to help sell the horror. This centuries old mind, trapped in a child's body, unable to properly experience things like sexually and romance, continually on the outside of everything, treated like a child despite her age and abilities...
If I remember correctly, she ends up being this extremely bitter murdering monstrosity, out of rage and spite over her existence. Despite her angelic, innocent face, she's the most evil of the lot. Partly because she doesn't even have the option of interacting with humans properly, and even most vampires treat her poorly.
And all because a character had a moment of moral panic, of pity for a poor child. A desire to do the right thing.
It's awful. And it's supposed to be.
This is so real it hurts...