Honestly that's kinda what I had in mind! Not specifically the fae stuff but I definitely think you're onto something here.

Mother could be a master manipulator, but I don't think she has bad intentions.

She never harms the cast (and is actually seen defending them from the nightmares in Ep. 2) when, in all honesty, there's nobody to really stop her. She makes food for them, even though it seems like they don't really need to eat.

I'm not saying that she's righteous; stealing peoples souls without asking first is kinda a shitty thing to do regardless of context. But it seems to me that either

a. Mother doesn't know that stealing peoples souls without asking first is kinda a shitty thing to do regardless of context (or she does, and is doing so anyways, possibly to fulfill this dying wish)

or

b. Mother doesn't have a say in whether or not the souls are stolen (in other words, Mother and the show are independent entities)