I would have written Malvina's relationship with Cynthy in a completely different way. I'd have made Cynthy the one thing that Malvina loved, but being Malvina, it would be a poisoned love. Malvina would be doing all these horrible things, then going home to Cynthy and saying "look what I did for you, sweetheart". Poor Cynthy would know better than to provoke Mama's anger, so she just smiles and nods her head. Malvina is so overprotective and coddles her and keeps her safe. From everything. Cynthy never gets to live a life of her own. Malvina genuinely thinks Cynthy is happy. So, after Terra, when Cynthy uses that knife to take her own life in front of Malvina, it causes a pretty bad mental breakdown. I wouldn't kill Malvina, but save her for later.
But all of that arc was long before my time in yellow, and I'm just a freelancer and not a developer anyway, so it's all moot. Fun AU stuff.