"The alternative is a reset or the loss of everything that could help us find a way out. It feels wrong to just keep them around while we mope. I'm in, so long as we try to make them understand that we shouldn't be killing ourselves!"
Sophia implored her friends, tired to see conflict, conflict, and more needless conflict after another. It's not that she actually wants to help due to moral reasons, but somehow, deep inside, she feels that everything will be lost and she would be stuck forever in a nightmare she never desired to happen. There must be a way to usurp the powerful control the murderous 'It' holds over the world.
As she understands, the timeline has somehow been reset, but she didn't notice it much, everything being an unconscious blur to her due to a mixture of fear and the instantaneous disintegration she experienced from Sans' blasters. The Continue / Reset screen only felt very oddly real, but mostly ethereal - a meaningless, pleasure-less reverie suffered by most of delusional people actually wanting to wake up from something they have trouble discerning as reality or its opposite.
Fear ebbs again, but with bravery gained from the journey, she manages to set those aside, and heed with the plan to stall the murderer. Monster or not, killing is wrong, and she's absolutely angered at the notions of killing or being killed by others. That is just wrong. Laykos proved to be the opposite of a murderer. There is still hope for monsterkind. Despite the betrayal at the hands of Gell. Beside Hedron's general indifference to the fates of the humans. They bear no genuine ill will - only a want to free themselves from their predicament. She can sympathize, and once her rage resided from Gell's betrayal, she can see that the monsters only simply wanted to be free - just like her - so they can see the outside world. She isn't willing to sacrifice herself for their cause, but if she can find a way - and she will, she will do everything in her power to free them.
This understanding of her emotions and her dislike of conflict helps her to gain DETERMINATION.