The best answer would need to consider If you are renting out a one-bedroom inside a home, or an entire one bedroom apartment? Do you have other rooms in the home you are renting so a family with children can rent?
If you wanted to rent to a couple, then queen would be preferred over double and over singles. Yes, older couples may prefer two singles. Two friends (or children) would prefer singles over a double. A couple would prefer a double. You can try with what you have for a few months and see how the bookings. If you are happy with your booking, then you can save yourself some money.