You're looking at custom-made.

just get a regular frame or platform and make it up like a daybed with pillows

we were running in that same problem. we took the hemnes daybed where you can extend the width and put a queen sized mattres on it. It works quite well in both childrens romms.

http://www.ikea.com/us/en/catalog/products/30080316

What about a fold-out sofa bed, permanently folded out? Replace the thin sofa bed mattress with your good mattress, and reinforce the folding legs to make them more sturdy.

Depending on the sofa bed style, you could probably make it look like the mattress and arms flow together naturally, with pillows and linens.

I believe the piece in the picture above was custom built by Jonathan Adler.

While not exactly the same, the "Snooze" bed from Ochre might provide a similar effect:

http://www.livingetc.com/gallery/main.php?g2_itemId=3961

http://www.ochre.net/en/display.product.php?furnitureID=furniture1&productID=f35

Try googling 'wing back headboard.' There are some gorgeous ones that have a somewhat similar look. Urban Outfitters has some cheaper ones but here's one I particularly like:

http://www.softsurroundings.com/detail.php?parentid=6104206&vcn=CSE&aid=performix&cm_mmc=PERFORMICS-_-StyleFeeder-_-DDI%20Link-_-k138683

if you order an upholstered wing backed headboard in a king, you can use a full size mattress turned lengthwise. a king mattress measures 76" wide, while a full size mattress measures 75" long. i love this idea because my daughter's room is 13' square and she can gain more play space in the front portion of the room since the bed will only stick out 4.5'.

I love michelabelle's idea of the upholstered wing back king headboard! Just make sure you're buying the "right" king sized headboard to match the full size mattress turned lengthwise. You want a standard king (sometimes also called an eastern king), which is the one that is 76" wide.

The right accessories make all the difference in making this look like a day bed....during the day. Some firmer cushions that you can sit up against, for instance, would be good. Avoid flouncy linens like a frilly bedskirt. Simple, modern items in your daughter's favorite color(s)...like 2 that go well together.

Good luck!

Michelabellle: I have been searching the web for full-size day beds and I stumbled on your suggestion. GREAT IDEA! I have one question though. How does the headboard work with the runners if you turn the full sideways? Did you just screw the headboard into the wall? Or is there a way to attach to headboard to the sideways full bed?

Thanks for the help!!

gortota: i haven't actually done this yet. i just thought of it while trying to simulate the look of the (most likely) custom bed. so, still trying to figure this one out. my dh is very handy and thinks we can make it work without having to attach anything to the wall, but i thought of another idea:
if we can find a full size bed with head board and foot board of the same height we can easily cut a longer piece of wood on a jigsaw and upholster that to match (or not) or if the head board and foot board are wood, leave as is.

so, sorry... while i think this is a good idea i haven't put it into practice yet. i will post as soon as we figure it out and actually execute. we're in the middle of a new house build so i'm a little preoccupied with finding a floor mount tub filler. thanks for the interest!

Belegant is Georgia based upholster. We will ship anywhere in the US.
This bed is on our etsy page.

Well, the headboard is on the page without the sides.The sides and base is not a problem to create.

Great upholstery and better prices!

www.beleganthomeandpet.etsy.com