My almost 20 year old does the same and it drives me nuts. I’d be better about it if he weren’t chronically late as well, but because of that I get pissed. It’s really the only thing we fight about.

Perfectly normal. Let her get her rest in before grad school.

There's an evolutionary basis for this:

https://www.science.org/content/article/early-bird-or-night-owl-modern-day-sleeping-habits-may-be-ancient-survival-tools