|I'm told she was legit depressed while writing this and didn't know how to end it|
Don't get me wrong; I get that characters have to be tested. It's just like life; things have to go wrong so that they can go right. Stories are about characters overcoming issues and problems and making things go right again after they've gone wrong. Things going wrong doesn't necessarily have to mean tragedy though. If you insist on killing a character then make it be relevant and necessary to the plot. Even if you do that, there's no need to further make life terrible for your characters.
One of the hardest things for me to admit on a literary perspective is that the major deaths, the ones before the final battle, are essential to the plot. Ultimately I can see how they all worked out. Except one. To this day I still haven't gotten over the death of Sirius and I see very little point to it.