I would definitely get a second hutch as soon as humanly possible. If you can tell she's pregnant it means she is quite far along, and having the buck in the same hutch as a kindling doe will stress her out greatly and isn't good for the babies at all.
You're not the first rabbit owner to experience an unexpected pregnancy, so don't feel bad about it. Mistakes happen, and I'm glad you're seeking help to make things better. What's important now is to protect the bunnies you've got (and are going to have soon). Focus on getting Shadow a new hutch, that's top priority. Make Ebony as comfortable as possible, give her unlimited food and a nest box, a fleece to keep warm if it's cold, and cover the hutch floor if it's wired so the babies have something solid to lie on.
First-time mama bunnies may not always know how to take care of the litter and often, some or all of the babies die. This is natural and not anyone's fault, don't stress out about having to take care of the babies yourself. Without mama bunny's milk, human-raised bunny infants often die even when hand fed kitten replacement milk. It is unlikely you will be able to save them. All you should be focused on doing is keeping mama safe, warm, and fed. Check on the litter at least once a day, and if there are any dead ones, remove them, but otherwise leave the baby-raising to her.
