OK, so I'm trying to flesh some things out.

My first question is: will the other characters be returning to the surface? If so, I won't be in too much of a hurry to have Neeza get down into the abyss. Otherwise, I'm going to have to get her down there.

Secondly: Just to minimize the need for too many introductions, I'd like at least the orphanage people to be familiar with Neeza. Though about the same age as most of them, she acts like a staff member, and helps out with some chores that the children are not expected to do. While her actions are caring in nature, her personality is otherwise. For example, whenever the orphanage doesn't have enough food, she tends to want to ration and reminds the other children that hunger is a weakness. During practice delves, she encourages others to push beyond their limits, but in an almost draconian way, belittling their 'weak flesh' and telling them that they must make their bodies succumb to their wills. While this has helped some, it has been off-putting to most. She would value Rags' intelligence and ability despite her bestial ways. Overall, she has been helpful in a practical sense, but has been extremely awkward. Most fellow orphans have no idea what goes on in her head and may have taken a liking to her, while those that think they have her figured out probably think it's best to avoid her and her ideology.

Something to that effect. But don't let my summary force your character's opinion of Neeza in any way.