[SKT Spoilers] Help linking my 7 yo daughter's story to SKT.

I'm running SKT for my wife and daughter. My 7 year old daughter has come up with this backstory for her character that her village was attacked by a spider lady who trapped her father (the leader of their isolated village) as a pony, and she wants to save him. I totally want to support her creativity so I'm trying to write it into Chapter 3. I'll lay out the basics that I've got in just a minute, but I'm looking for a good way to tie it in to the giants.

So my thoughts are to place her village inside the High Forest where they live and work to protect the land under the blessing of a unicorn (because 7 yo girl). A female spellcasting drider has captured and imprisoned the unicorn, and caused her father to be cursed into the shape of a unicorn.

I plan to use giant spiders and a few cultist types, and possibly throw in a stone giant or two in order to tie it into Thane Kayalithica's story since stone giants are probably the most logical to have run ins with the Drow or a drider. I was thinking about possibly replacing the Uthgardt barbarians in Deadstone Cleft with Drow that promised to help her cleanse the surface and return Ostoria to the giants in exchange for things(?).

In reward for rescuing her father she's going to get a magic item I've worked up that will let her take the shape of a unicorn once a day without any of the unicorn's magical abilities (I'm not really worried about balancing it, since it's just her and my wife playing).

Thoughts?

Why would the drow be working with giants?

Would the rest of the stone giants know Thane Kayalithica is working with drow or maybe just a select few?

It doesn't have to be terribly compelling, but I'd like it to make sense for my and my wife's sake.