Mrs. Waggoner lives in City View Apartments on the floor above Garik Shayk.

She is the "old dame" of the building and one of Garik's few friends besides Marina, at least in the apartment building. 

Mrs. Waggoner keeps an eye on Garik, askes how his aunt, Irina, is doing, and generally provides a grandmotherly influence that's a stabilizing rock in Garik's sometimes volatile world.

If Garik needs help with something that's outside his aunt's skills, it's Mrs. Waggoner he turns to. Whether he thinks of it this way or not, he cares for her and goes out of his way to stay in her good graces.

We first meet Mrs. Waggoner in Book 1 of The Human-Hybrid Project, Shattered by Glass.