Stiles’ mother was a…

So things in Teen Wolf are rarely mentioned by accident. In 3×02 ‘Chaos Rising’ Stiles said:

“This girl…our mums were best friends before mind died!”

Heather could have been any old childhood friend. They didn’t need to bring Stiles’ mum into it did they? I guess it adds gravitas and it makes her more important to Stiles, that he find her, because she is a connection to his mother. Yet it’s not like Stiles wouldn’t have wanted to find her anyway is it?

Making this extra connection to his mother is intriguing it hints, maybe, that the reason why Heather was taken is connected to her??

We know that Stiles’ mother died and that was long and drawn out and she died slowly in hospital from Stiles’ hallucination in 2×09 ‘Party Guessed’.

“You know, every day I saw her lying in that hospital bed, slowly dying…”

But we don’t know what she died of or anything else about the circumstances of her death other than that.

Was she involved with the Supernatural and did this lead to her death?

And now is Stiles involved in it too?

Was his mother a spark? What even is a spark? Did she create some kind of monster with the power of her imagination and it lay dormant until now?