She says she's lonely and has no friends okayy and she hasn't drank in four days why hasn't she drank? When I ask if she wans a drink she says "no I promised myself I won't drink" is she trying to kiill erself?

Your sister hasn't drank in 4 days and you haven't drank in 2? Are you BOTH trying to commit suicide?

https://www.askmehelpdesk.com/emotional-wellbeing/am-suicdal-658650.html