I feel there's 50/50 chance Yui will be saved somehow.
As for people who still don't understand why Silkie went so far to try save Yui, you guys need to remember she's a
serial killer, she is for all intents and purposes basically insane to some extent, she doesn't have conventional morality, it doesnt matter if Yui is a child, all that matters is that she don't think Yui is a bad person, if she don't see someone as a bad person then she won't kill them, consequences are irrelevant because only her own personal morality matter.
Actually, thinking about it, Yui seemingly had her heart and brain cut, so she probably won't survive