I really don't want to sound cruel, but...the man is dying. He cannot be saved. If he wants to drink a beer, let him. It kind of goes along with the "doing what we can to keep him as comfortable as possible until the end." Denying him a drink now wouldn't serve any purpose at all.
My father died in much the same way. He was so yellow and bloated we couldn't even see his knees or ankles. By the time all that happens, it's too late to save them. If he wants a beer, let him have it.
Is there any possible way she can explain to her employer that her father is dying and she wants to be with him? Surely there is some way they can allow her to have this time with him.