Threatening to kill someone is beyond just unravelling. At a minimum write those conversations down & if they are written (text, e-mail) preserve a copy.

I wouldn't worry too much about the timing, as you can tell the kids first, give it a few days for the 2 weeks to almost run & then let her know. If one of the kids tells her, it is likely too late for her to get to her L & screw things up.

Good luck.

Me: 50 W:43
S6, S3
M: 12 yrs. T: 17
M is bad & Not happy Bomb Mar '14
S 5 Feb '15
D Bomb 13 Apr '15 (but "no hurry")
DB Coach May '15
Wants proceed on D Aug '15
Starting 1-on-1 negotiations Sept '15