I, at least, have some experience in what it is like to lose someone close, Joanna. It is not quite the same, since I am not human, but I have felt loss, and pain, and a great many other things since then. I understand more than you realize.
I think the only person who should be taking responsibility for her death is the one who directly caused it.
The point of angels is, again, far more than aiding you in your lives. We are tasked with far more important matters. Occasionally our orders are to aid you, but it is a lot rarer than you humans seem to expect it to be. Additionally, the point of prayer is not simply demanding and expecting aid, it is communication with our Father, and if He chooses to intervene, He will. His Will and knowledge are far greater than ours, and he has provided you all with the ability to care for yourselves and for each other - but you are mortal, and you will, eventually, die. How that happens does not matter, and meddling in the affairs of the afterlife is not something to be done lightly, or on a whim.