"I don't have as much time as you guys"??? Bullshit.
Everybody has 24 hours in the day, and we all have to make our own decisions about how we will use our time. Picking up after oneself is included in the bargain when you live with other people and that's that. Whatever it is that leaves her less time to do her dishes was
her choice. If she chooses not to have time for basic courtesy in a shared space, then she'd better start paying somebody to clean up after her because it certainly isn't your responsibility. Better yet, you should tell her that if she wants to overlook basic cleanliness in order to save time, she should stop showering and use that time to do her dishes. I'm sure she'll love that suggestion.
Enforcing the rules isn't a matter of principle in this case; it's a matter of decency. Nobody likes to live in a sty but a pig. Good luck in dealing with her.