this feels very thought-crimey to me, but I think I'd have to actually see that chats to really decide. Like is she making plans/asking for advice? is she just talking about her feelings exactly as if it's a diary?

She is not being charged with planning, just making threats in a place a person could read - the person being employees of the company.

Basically, under this interpretation, any personal note you store in the servers of a company could qualify, even if you didn't ever imagine someone would read and as such you couldn't have thought about it as a threat