The question may be as to if she was dealing with depression & anxiety before everything that happened on her business trip?
Situational depression can look exactly like the chronic major depressive order. The mental health providers I had didn't specify between situational or not even though I had never experienced it before. After it hit, it lasted for so many years (13+) & they had no clue how to sort through all the situations that started it let alone a long term condition that had fed into the breakdown when it happened. When you have lived with something that actually feeds into a breakdown you have no clue because after a long time, it becomes a normal in your life until that "straw that breaks the camels back" happens in your life. Situational & clinical(cronic) have the same outward symptoms. Only way I knew was because I was finally able to walk away from the situation & the person & the depression didn't follow me across the country. Took me a few years to process it all in therapy & learn new skills so it would not happen again.
Guess if even mental health professionals can't figure it out, only those of us in our own lives can with time & experience based of what we understand within our own lives. Wish it was more obvious because I thought life would never change during those years & I gave up many times