Trigger warning for suicide and self harm

I haven't always had a good or even civil relationship with her, but lately we've been managing. She came to my city to visit her mother so i went and visited her for half an hour

I noticed she was subdued and she opened up. She cried a fair bit as i held her. She talked about being lonely and frightened of selling her house. Her mother is in ill health and her dad died a little over a year ago. She feels really lost.

She mentioned she'd self harmed a few months ago and it'd took the pain away for a bit. She says the only reason she hasn't killed herself is she can't leave me an orphan.

She felt so guilty for telling me all this. She feels like a burden on my sister and I (I'm 21, sis is 26).

I don't know how to help her.