Sounds like you're doing a lot of things right. The big thing that I'm concerned about is the fact your chin is right up against a big window. As you know they are sensitive to drafts and heat. If it gets over 75F it could cause brain and organ damage in a chinchilla. Sometimes at lower temperatures if the chin is active. The igloo which is made of translucent plastic probably gets hotter on the inside in direct sunlight. It is possible the stress from the heat and light is preventing her from sleeping during the day and causing extreme irritability and sleepiness that may explain the behavior.
These symptoms could be of other potentially serious health problems too. Especially if she is having trouble running on her wheel as opposed to not running on it (not all chins like wheels). I recommend a vet checkup by an exotic pet vet that specifically treats chinchillas. It may be time for a tooth exam too especially if she is not chewing on her toys and biting you which may indicate there is pain somewhere.
I also recommend getting a wooden hutch that allows good shade for sleeping and highly recommend positioning the cage away from the window and out of any place where direct sunlight can fall.
Other things your chin might like would be wooden shelves in the cage to jump on and hanging wooden toys to add interest. You can try different shapes of wood toys as well.
How is her food and water intake? You can tell if they are backing off their food if you notice decreased fecal output with unusually small and hard feces.
I've been looking around for wooden hutches to solve that lighting issue. Unfortunately there aren't many places in the room where she can be without sunlight so perhaps blocking out the windows with blankets and other such things will help?
Her food and water intake in takes looks fine, I see her eating and drinking fairly often(especially after play time) and her poops don't look any bigger or smaller than usual. A few months ago though she was having some big poops so she was eating much more those days, but they've gone back to the tiny ones.
That sleep thing is what I'm most concerned with now that I know. I'm going to get right on it.