If you haven’t found Abby in Drustvar, I would suggest you do. She is creepy as heck. Fair warning though – don’t do it before bed. It isn’t so much that children are always portrayed as evil, it is the creepy little song she sings and the way she says things.
“Our poor little Village is dead.”
“All the people have gone stiff or fled.”
“There is no more noise…”
“…except me and my toys…”
“…just like all the dark birdies said!”
It may not just be the words but combined with the tune, it is a little spooky. She asks you to help her find her toys for a tea party and that seems all ok, until you find a cat and I think (as do many others) the she killed the cat!
As you find various parts of the quest chain she appears as says super creepy things, I give you exhibit A which seems pretty sort of standard and expected in a zone full of witches and covens:

Then she pops out with something like this:

It is just creepy. Then you finally get invited to her tea party:

If I have learnt anything from watching too many supernatural shows like Supernatural, Haven, Charmed etc it is that whenever there is a symbol on the ground and a creepy kid – something bad is going to happen right. RIGHT?!!??!
There must be a trigger to her appearance as she wasn’t there the first time we ran through the area. I would suggest it is linked to the quest chain for opening up the footholds (and likely reputation) so definitely go back and check her out if you haven’t seen her.