Hi jds,
We have a trundle bed (a daybed with a bed that collapses so that it can be stored under the daybed. They are both twin mattresses.) We’ve found that this works well. Single guests have more room as our bedrooms are small. When we have a couple we tie the beds together with bungee cords. We’ve had a lot of people traveling together who don’t want to sleep together (parents and children, friends, work colleagues, siblings, etc.). Once we had a male and female friend who didn’t want to sleep in the same room and asked if one of the beds could be moved to the living room. The really strange part is that although we are very clear that we have two large dogs who are not low dander the guest who slept in the living room where the dogs have free reign was allergic to dogs.