What is the concept of personal space?

The lady here has been standing and leaning on my seat from 2 hours. She had waitlisted seat and boarded the train. She didn’t get any seat to sit on. Trying to be polite and not said a thing to her because she is standing on a 4 hour long journey, and the only reason she stood next to me because she Must’ve felt safe, but now im getting pissed.