How do you find out where someone died, what they died of and what cemetary they're at?

Eight days ago I found out that the mother of my child (my ex-girlfriend) had died on the internet. I found out the date she died, what the city of the last address she had is at (differant websites gave me differant cites for addresses though) and what her social security number is. Now the three biggest questions I have now is what I wrote for my question. Chris