I don't want to give it away since I don't have an easy way to mark spoilers here, but there is a direct hint along the same path you used to find a newspaper advertisement of a local business that featured a picture of one of the Roottrees. At some point you come across a list of different businesses/organizations, and she's related to one of them.
If you'd like more details the discord can fill you in, but hopefully that's enough to go on.