I'm not going to help my depressed friend
Why don't you want to help them?
It really annoys me to see her like that.
If you were really her friend then you would want to help her. You can get professional help for your friend at the very least.
I will just let her be depressed. It is good for her to know what a real depression is.
I think that it is wrong not to help a friend when you know that they are depressed. You know how lonely it can get and you should want to save them from getting to that place.