I honestly don't even know what happens if you call the cops on someone that's threatening suicide, so... Yeah. You taking the consequences she'd have to face into consideration is honestly being a way better friend than she deserves at this point.

From this end, it seems like a lot of her cries of suicide are just for the attention. But if you ever get a gut feeling that she might actually do it or she says she's going to and logs off for a long time, I say go ahead and make the call. It could be a false alarm and you could get a ton of shit for it, but on the off chance that it's the real deal, well... Consequences are a lot worse there.