Well, Acctually, Schala was talking normally, it just seemed that because she was battered so much, she couldn't stand up, and was believing that Crono would run away, but he didn't.
You think about it. Schala had to constantly drain energy from the Mammon Machine, finally to a point where she was zapped by it. She then had to go in with the Mammon Machine, get zapped again. After what happened with Crono, she managed to stand up and use the last of her pendants powers. then she was sucked into the Mammon Machine again with the gurus, who were then transported to different times. Then she had to watch her brother get sucked into a portal to who knows where and she still like didn't go crazy.
But the strongest part about her is that she acctually survived being in the DBT, ESPECIALLY AT LAVOS' MERCY OR WHATEVER!
Even when Marle came back from the DBT (most likely) she was like Omg, I felt like dying etc. etc.. When Schala was freed, she seemed normal and as usual.
She withstood going crazy for a hella of a lot of time. And she thought about others than herself. She even reached out through time to save Serge, send the compassionate side of her out into the world etc. etc. and try to withstand Lavos aslong as she could.
No one could ever withstand Lavos mentally >.> Physically maybe, but what Schala had to go through is way harder than what Crono had to go through. I mean, when I played the game. Crono was lvl 24 when he died...