Where is the line between disability and tween attitude?

This is something we struggle with daily. I don't consider myself a "precious little snowflake" parent, but I find it hard to judge when Caitlyn is being purposefully defiant and when her disability is interfering with her doing something. It can be anything from making her bed, to remembering to bring something specific home from school. This week alone she left the camera her Big Sister bought her in her desk at school, still has not brought home the Tree Ring assignment from her Science Journal, and we had to deal with a major meltdown over cleaning her room Friday night so that she could go to a special ed camp this weekend.

I am just at a loss. I feel like if I continue to expect her to receive no penalty on this tree ring paper (because I've asked multiple times now for the teacher to make sure it's in her binder before she comes home) that I'm helicoptering and preventing her from suffering the natural consequence of an action. On the flipside, I have asked the teacher multiple times, and without that grade, Caitlyn's failing science this six weeks so far. What to do?