She can't completely rule out that this is something the colonists brought with them, but it doesn't seem likely. This universe isn't magical and while someone from outside the universe could have come in and done this and left, that also seems unlikely.
So, it's likely something on the planet. It could be contagious. It could be environmental. Glen hasn't eaten any local food yet and she has enough of her own to last a while, but that isn't exactly a scientific test.
She needs expertise she doesn't have. She does not have the capability to contact someone from home without opening a two way connection and if this is contagious that is a very bad idea.
So, she she'll need to recruit a local biologist. She isn't in a tremendous hurry. If she wanted to leave to avoid the chance of whatever this is happening to her, she would have done that already and the people here have been living with whatever this is their entire lives.
She reads papers. She looks for researchers who seem humanitarian and researchers who seem insatiably curious and researchers who may be less skeptical than is typical and researchers who have tackled problems remotely similar to this.
This takes her most of the day. She eats her food she brought with her.
And then she compiles what evidence she has. The comparative statistics, a summary of the vast difference in how the cultures she's familiar with experience art and beauty, the history of colonization and how it makes more sense given the premise that people on Earth are more like her.
And then she goes and tries to convince people. She'd prefer to do it remotely, but the ability to teleport adds a lot to her argument.