Could you help me explain the meaning of "顺其自然"?
Well, I am a Chinese, so I think I can have a try.

"顺", means let it be, or just like the song from the movie Froze, let it go.

"其", means itself.

"自然", means what it means to be.

So, put it together, it means, just let it be what it should be, do not intervene. It usually used to comfort someone who just failed something.