Actually Maxi does speak up for herself, She's actually the one with the most character development but honestly foiled with the way the writers choose to write Riftan and yet still glorify and romanticize his own abuse towards Maxi. Her inability to speak up for herself in the case of her father dragging her back to her original home, is not her fault at all either, if that was what you were referring to=

Over the years, from the start to now, I've been marinating this manga a bunch of times. I've finally read lots of spoilers and had decided I'll drop this. It's a bumpy story and the main characters only give me headaches.
Riftan is an overprotective stupid asshole, always treating Maxi as a child and never considering her own feelings. He had already done wrong to Maxi by sending her home, which I don't really blame him since he only wanted to protect her and plus he didn't know how Maxi was treated back home (but he could have comforted her before sending her away after losing a child and waking up from a coma), and he's sooooooo stubborn man.
Maxi, instead, is too much of a pussy. From what I saw, she didn't really do anything bad in my opinion other than not speaking up for herself many times.
The story has a good ending, but not worthy of my eyes to read.