She didn't make it.
Turns out it most probably wasn't twin lamb disease after all. More likely a tumour or obstruction or something else internal.
She didn't really respond to the glucose drenching and syringe feeding (or ABs or vitamins or calcium). The abortion wasn't happening either 40 hours later. She was still alert, even licking my face but very weak and getting bloated. Agreed to take her to the vet for last ditch examination and possible cesarean. I left her for 20 minutes to get the car ready for the trip, when I got back to her she was convulsing and choking violently, fluids coming out her front and back.
Vet is only 10 mins away... the longest 10 minutes ever. She tried to relieve the bloat as a first measure but there was only fluid coming out which shouldn't have been there, and vet concluded there was something very wrong inside, nothing to do with pregnancy or infection.
It was only kind to put her to sleep there and then. I'm berating myself that I could have spared her that last day of suffering.
Devastated. RIP little Bee.