She might be so self absorbed in her own life that she didn’t know he wanted to end it. Happens all the time
I don’t think she’s that ‘unaware’.
It’s just my opinion, but I think they both want to move on, and have found a way to do it.
That happens, too. Nothing wrong with it, as long as it’s a decision mutually decided upon and carried out respectfully with regard to one another, to family, and to society.