I took a large 2" thick styrofoam block and cut two pieces the same size 12" long x 5" wide x 2" high

I then covered one piece with black cotton fabric for the sheet and pined it underneath to hold it in place.
This piece is the mattress.

I created a green ruffle and pinned it to the other piece for the base of the bed.

Notice I left one end without the ruffle. This is so it will sit snug against the headboard.

I flipped the "mattress" over and placed it on top of the base.
I then used more pins at a diagonal through the base at the top into the mattress. This will prevent them from coming apart during "play". The pins are hidden by the pleats in the ruffle



You could use a wood glue if you would like them to hold together permanently. I used pins so if I wish to change the ruffle or sheet in the future I can.

Now for the fun part.

I constructed the canopy with a round piece of styrofoam cut in half to give me a semi circle. You can see where I also cut into the corners for the dowel pieces to fit into the styrofoam...This gives a neater finish.

I painted my dowel black.

The headboard is nothing more than a piece of cardboard with wadding on the front for padding and then covered in the same green fabric I used for the ruffle.

The headboard should be cut to fit between the dowel rods. You want the the dowel rods to be the same width at the headboard as they are at the styrofoam so the posts will be even from top to bottom.

To hold the headboard in place I wrapped the green fabric around the dowel posts before gluing the fabric to the back of the cardboard.

The white dots are adhesive Velcro dots, this allows me to attach the headboard/canopy to the walls without it being permanent fixture.

Lastly I added the curtains, then a smaller green ruffle and then trim to cover the styrofoam in the canopy.

Tied the curtains back to the "posts"

Place the mattress and base in front.

Now it looks like a bed.