I'm going to tell my roommate to take a shower and clean her side of the room
Why do you want to ask her to clean the room?
She's going to smell up the room and live in a filthy state.
Your roommate should clean and shower. Creating a bad living environment for someone else is wrong and rude. You should not have to put up with that.
The roommate made the place messy so I don't care.
Your right to make your roommate clean up after themselves. It is part of her obligation as a roommate to be hygienic. If she doesn't want to, you should remind of the legal agreements you signed before moving in.