Sometimes nothing works- we went to the Vet several times and it was just age. You could do diapers but I would think your B would rip them off. I went and got some plastic crib liners and put those in a few places where my boy sat and lay down. He refused to go outside sometimes and when his eye site failed he was even more afridi of the dark.
I just went through this with my boy and I call it Dogheimers. If you are okay with most of the behaviour then bu a bunch of Pee Pads and spread them all over. There is no magic pill or potion for this. Love her and enjoy her as long as you can.
You may have to make a VERY tough decision soon.