Great questions!
I think there is a good chance something about the relationship of this woman to him has to do with triggering this mass murder.
I have seen it reported that she may be originally Indonesian but elsewhere that she was a Filipina. If she is in the Philippines now, that might suggest the latter.
Did she marry her way into the Australian passport? If the marriage to Danley did not produce a green card, was she hoping to get one through a marriage to Paddock? Does she have a habit of bouncing from white sugar daddy to white sugar daddy? Or maybe she decided that being with Paddock was not worth it and broke it off? Or Paddock balked without a prenup?