I don’t think any of the things she said are deterministic or objectively descriptive. At the same time I think she does capture some essence or wisdom from her multitude of experience and her knack for noticing this and being able to put it into words.
Painting is not just capturing the pixels of light on canvas. This is what children consider painting. Great painters capture emotion and energy on canvas -- that's part of the essence that I am alluding to. That's what separates an artist who can realistically capture a scene from a master. Emotionally mature people who experienced life can recognize that emotion and energy in great paintings.
It's kind of like math. Some proofs and formulas are considered elegant or even beautiful. To the untrained eye they look like letters, symbols, and numbers.
Take Euler's identity: e^(i*π) - 1 = 0. My kids see gibberish, since they are in grade school. I see something surprising and neat but don't fully understand it. I've spoken to people who have a deeper understanding of math who can talk wonder about this simple-looking equation and use words of feeling to describe it.
No, her job depends on making the married couple happy, which is not at all the same as 100% accurate representation.
People attend weddings for a lot of reasons. Sometimes it's full of your most favorite people in the world, sometimes you only know a few people in the room. Sometimes you have a lot of fun, sometimes the entire thing just feels like a massive inconvenience. Sometimes it stokes the flame of your relationship, sometimes it occurs during a time when your relationship is under some stress. Sometimes I'm dancing/partying all night, sometimes I never leave my table and leave before the cake is cut.
Anyways, I'm sure she does see a lot of these patterns and you can try to infer a lot of things about the people, with some reason, but people are fluid and this is too small of a sample of their life to really know anything other than how this group of people interacted on a single night of their lives.