Hi Vegas66.
I don't know if you'll make it back here or not but I've lived with a family member as well as an ex-spouse behaving that way. Sometimes suicide threats are used to manipulate and try to make a partner feel too guilty to leave.
Suicide threats are listed on the Domestic Abuse check list I used when I was in a very abusive relationship with a husband who kept threatening suicide. I left and he never committed suicide like he threatened. It was all manipulation.
His depression was real, but that was also something he manipulated me with. He would get super depressed when I didn't revolve my life around him..
That may not be the case with yours but I thought I'd put it out there as something to consider.
I hope you're well and she is getting help. Update us if you can.