Send them back.

Why not start with realizing that your friend is human too, and unless you have reason to believe she deliberately did this to spite you, forgive her and move on.

I wouldn't accept the mistake and take on additional problems it has caused. The decorator made a mistake and needs to be accountable for her error. Just because the delivery was accepted doesn't change the fact that the wrong beds were sent and does not absolve the decorator from her mistake. Yes, mistakes happen, but the decorator is ultimately responsible to give you what you requested. Are you afraid to breach the subject because she is a friend, or is she not willing to make it right?

It sounds like there are a couple of issues here. If the delivery ticket showed two beds were delivered, when did you find out they are the wrong beds? Can you bunk them, or were you wanting singles and trundle beds to save space?
If the decorator sold you single beds and trundle and that is for what you paid, then she needs to pony up on the deal.

If the beds she sent will accept them, you (or she) can buy just the trundle part separately.

Thank you for all the comments. We paid our bill and havent heard anything from my friend. I'm not going to take issue with that, but was hoping for some sort of construction solution. Because the the beds are totally upholstered, head, foot boards, sides, and were custom made in Houston and moved to FL by the upholsterers, I dont think , financially, that it is feasible to send them back and get new ones. I'm going to check on 1 bunk bead that will fit with the one single in the space. If you know any really nice, not beachy bunks, let me know. thanks, kathy

The decorator should correct the mistake!

If you were the decorator, would you want your good friend to simply swallow an error like this and never mention it? Probably not.... I'd definitely call her, explain the situation, and give her a chance to make it right one way or another. There may be a middle ground or creative path that is win/win, but you'll never know unless you discuss it. At a minimum, the decorator should propose and pay for a solution that gives you the sleeping accommodation that you ordered and that you need, even if it is a different piece or design.

As far as ideas generically, I think you know them all: loft, trundle, Murphy, sleeping bag, hammock, air mattress, sofabed, folding cot, 2 kids in 1 bed (if they're small and well-behaved, this may work if they sleep in 2 different directions, i.e. heads at different ends).