So, this came to mind and it worked out really well.

Materials:
- Wire rack (the ones made up of squares that you build yourself)
- 1 pillow
- 1 large piece of fabric
- 3 sheets
- 1 pillow cover
- Small doll-sized pillows

This is what it looks like before I dressed it up.

Pillow for the mattress. Just wrap the pillow in the fabric and let the rest of the fabric hang off the edge.

Add the one sheet to the left and another to the right. The last sheet on top hangs slightly over the front and the rest drapes off the back. The result is this!~

Use the pillow cover as the blanket and you can take smexy pictures of your dolls in bed. XD
Then, when you're done, just dismantle the bed and store it away until you need to use it again.
Set up time: 30 minutes