I think of her as having two groups of friends. The first is a broader circle that knows her fairly well. They have class together, maybe have been to Hogsmeade or just hung out in the dining hall. They know she can sometimes be moody but mostly navigate around it. They see more of her rebellious but fun side.
The second group is a smaller circle of close friends that she's more vulnerable with. She's more likely to talk to them about her past or vent to them when she's feeling low. She doesn't want to chase them away when she's upset because she trusts them. This is her "ride or die" gang. I imagine these people who bond over similar "ghosts" in their past, or perhaps they reach out to her because they're sensitive and good listeners.
I'm open to ideas on all ends.