It's most likely SARDS, Sudden Acquired Retinal Deterioation Syndrome. The rods and cones of the eyes stop working overnight. It happens in pure breed female dogs after the age of seven. Sorry, there is no cure. The very same thing happened to our dog. She acquired glaucoma a bit later. Her eyes swelled up so bad, no meds helped. We had to have both her eyes removed because of the severe pain she was in. From the swelling. I say this not to upset you, but you need to know this is a distinct possibility. Your story sounds exactly like what happened to our baby.
You will need to retrain her. Get a clicker and have her follow you around slowly through the house. Talk to her and make more noise as she learns to memorize the layout. Do not move furniture. Instead, if she is about to run into anything, tell her to stop and turn as you gently prod her in a safe direction. After a few weeks, she'll be able to maneuver with little difficulty and much more confidence. Play with her, give her treats to keep her busy so she doesn't get depressed. And stay positive!
I would take her to an animal eye specialist. Most regular vets won't know what is wrong. And don't worry. With dedication and lots of love, she'll do great. Our baby did. Most people have no idea she's blind 'til they see she has no eyes. Best of luck to you!