I'm sorry RC. I did read that you had put a piece of cardboard below the roost; twice in fact.Yes that is why I rigged up a poop board under her. I am 99% certain she pooped nothing but liquid all night.
Yes, you are right to be concerend if she pooped water all night.
But, you did mention that her crop was full at roost time and empty in the moorning so food is moving past her crop and one must assume that it is reaching her gizzard.
I think you are right to seek a vets advice in this case. I know that chickens can get constipated but I don't know what the vetinary advice is in such cases.