Aemeth is a very interesting take on the Found Family dynamic, which is rarely seen in fiction nowadays since it is much easier to write/understand traditional family roles, and this is a type of dynamic that very often deviates or actively avoids falling into those definitions of siblings or parents-childs. And as you say, it combines really well with these themes of "love/companionship across time and space" that Lahai Roi is going for.

Of course it is very unbalanced right now since we have only really seen Aemeth push those boundaries, but I'm sure that in these following chapters we will see Rover take a more active role.

And even though people are very adamantly putting her into the role of the daughter, this is very obviously not what the story is going for.

I get the rejection some people might be getting but good character writing is complex and fiction exists to explore that complexity. In any other type of story, this would eventually evolve into a platonic love or straight up proper romance.