Welcome to planDisney Sondra!
Disney's Port Orleans Riverside is truly a gem. The grounds are beautiful and it is so peaceful. It is the perfect vacation break from the hustle and bustle of the theme parks. Your friends have made a great choice booking this resort.
The best option if adding an additional guest at Riverside is to
book a room with a 5th sleeper. These rooms have 2 queen beds, then a single bed that pulls down from the wall. Not all rooms have this option, so it would need to be booked specifically.
Rollaway beds are always a big question mark, as sometimes you hear resorts may have them, but available first come, first served. If you are planning on this route, I would have your friends call Riverside directly to find out availability and pricing. With room size at about 314 square feet, it would be a tight squeeze to add the additional bed, but you can certainly inquire with the resort.
While at Riverside, hop on the Water Taxi to
Disney Springs. It is a lovely cruise down the Sassagoula River where you will pass Disney's Port Orleans French Quarter, the Treehouse Villas, and Disney's Saratoga Springs Resort. While at Disney Springs, enjoy shopping, dining, and you can even catch a movie. The fun just keeps on coming!
I hope you get the details worked out and can experience Walt Disney World with your pals. Enjoy!
Cathy