Rooms come with two queens or a king and pullout sofa. You can get a rollaway for an additional $25 or $30 per night. Some people like to bring an air mattress or something to avoid the fee. Rooms at RPR are a little smaller than at HRH so take that into consideration as well.
We stayed in a standard room at the Hard Rock with an air mattress for one child. I am thinking of doing the same thing at Royal Pacific next time. They were fine with us having 5 in the room at HRH, I am hoping it will work at RP as well.