Even if you do know the woman and could contact, I would STILL let it go.

Clearly you cared deeply for your friend and I am sorry for your loss. And perhaps this sense of wanting to "do something" comes out of that sense of loss you feel. But with all the caring in the world I mean this...

...it is not your affair and you getting involved is hubris, not love.

Let all involved mourn and move on, and what happens naturally happens.