Hi again Member 887 --
Wow, 15 years of coping with her suicidal thoughts is a lot. You must be beyond tired

It's okay to want to "just" be her parent, not her therapist or interventionist or EMT or whatever. There are paths forward to step out of the role of rescuer, though it may take facing some fears about losing her or about how much control we really have over someone else's choices.
How does she communicate that she has suicidal thoughts -- text? phone? email? other?
As far as you know, are you the only person she tells? Or do you think she tells other people (family members, friends, social media posts...)?
And in the past, how would you approach it when she tells you she's feeling suicidal?
Fill us in, whenever works best for you --
kells76