Not before she jumps but I think most people got it from this in the previous episode:I don't agree that she was suicidal, at all. Where do we get any hint of that before she jumps?
Buffy #1: I felt it. Glory will beat me.
Buffy #2: And in that second of knowing it, Will...
Buffy #1: I wanted it to happen.
Willow: Why?
Buffy #1: I wanted it over. This is ... all of this ... it's too much for me.
Buffy #2: I just wanted it over.
Buffy #1: If Glory wins ... then Dawn dies.
Buffy #2: And I would grieve. People would feel sorry for me. But it would be over. And I imagined what a relief it would be.