Hey Nicole, just jumping in because I feel some confusion between “Discourse the tool” and “A community using Discourse”. It’s not like facebook or other social platforms where creating an account lets you step into a pre-existing social space. When you create your group (or community) using Discourse, whether it’s self-hosted or by signing up for an account on discourse.com, it’s as if you have received an empty conference venue, or the keys to the restaurant. So you (or is it your client?) then need to design the community in the Discourse tool and also get people to join and take part. It’s quite different from, for example, creating a facebook group, where you can reasonably expect people to stumble upon it and join because they’re already using facebook.
So, to answer your initial question: Discourse can definitely work for the kind of community you’re describing, but it will all depend on how the “community manager” (you? your client?) sets up the platform, manages to convince people to join it, and then manage the growth of the community as more people get on board.
Hope this helps!