Raw spiritual emotion

My sister is a sap. Cries often. I always thought this was because she's a softie but recently I was asked to believe that God had something to do with it.

Here's how the conversation went down:

Her: I know I cried on the way to my wedding.

Me: Why? Was it joy? Fear? Excitement?

Her: This is going to be a shock: I cried out of raw, SPIRITUAL EMOTION.

Ok, haha only she was dead serious. She holds there is a substantive difference between spiritual emotions and the other types. But how do you differentiate between an ordinary emotion like joy or fear and a spiritual emotion? She can't say. And the fact that a clear distinction is not apparent should lead my sister to treat her experience with caution. Shouldn't it?

There might also be a philosophical problem. My sister, in brief, holds that something from the spiritual realm affected her, overwhelmed her and reduced her to tears. The problem is that everything in the brain is fixed by natural law. Our thoughts and emotions are a function of our grey matter. The neurons fire, according to the laws of nature, and we think or feel. My sister believes that something spiritual -rather then material- came in and overrode the system causing her brain to behave in a way not governed by the laws of nature. This is the"raw spiritual emotion" that made her cry.

But what are the grounds for her belief that a material brain can be controlled from the outside? She has none. And this also makes me doubt.