She is just someone who doesn't know how depression works. Depression isnt linked much to how things are going. Thats the problem. You can feel shit when everything is going great and then you feel even worse wondering what you will feel like if your life gets worse. It also makes you think if you cant be happy then, then when can you. For a lot of dolk the whole, well at least i am not in Somalia doesn't work.
Dont get annoyed with that lassie. Just accepts she doesn't get it and ignore her.