Flight was the only resource left to her.

The poor, bewildered mind, groping so darkly, fixed on this one idea.

She would not kill herself.

That would deprive her of all hope in another world.

She dare not live her present life, but flight would save her.
People would only think she was mad for running away, and surely when Allan Lyster saw what he had done he would relent and persecute her no more.
She was not herself when she stole so quietly from home and went disguised to the station.