What we know is that when Akira tried to tell her about the resets, that triggered something in her mind. She says that she saw a light and that caused her to choose (or be compelled) to jump.
Later, she said that by doing so she instead was completely enveloped by darkness and (somewhat) makes references to the the wishing well. I went into this in a previous post that talked about Akira's eyes.
My take is that she understood the nature of the resets and had an insight on how to break free. But many other things could have happened. What's also certain is that it didn't work, actually it turned out very bad for her.
EDIT: As an added note, it could be argued that Wires was the one that fixed her (after the reset, by doing a proper job with her memories - we don't know who brought her back in the moment it happened, and left her with the memories of the suicide until the reset), but I don't know if that matters.