Welcome to the Exotic Pets Forum RandiW! With a Coatimundi you may need to try a few different things. They are a bit different than many mammals that are litter boxed trained. Start with a small area with a litter box or one of those little potty pads used indoors with small dogs. If she doesn't like the litter try shredded paper.
Any time she eliminates either pee or poo make sure some of it is in a the box or pad. Just so that there is a scent of what you want her to do. Gently place her in the litter box or pad when she begins to go. Never, ever punish. With persistence and time it will pay off. Other than the small scent spots, keep the litter box or pad clean. No animal wants to walk in a icky box or pad.
If she appears to be shy about eliminating in public, give her a private spot. After time, increase her confined area to include more space.
Again, welcome!
Coatimundi article 
