I was born with a similar deafness, but in both ears. Bilateral Congenital Aural Atresia. I chose to have a Cochlear Baha hearingaid implant. When I was younger the doctor said they could, basically drill through my ear and it might work but would likely leave partial or full facial paralysis. So I opted out of the surgery. I've had inner ear workings just closed where it would normally open to your eardrum.
It is hard to say with knowing more about her ear. There are three parts to our ears: outer, middle, and inner. Sometimes the problem is just the outer ear, sometimes outer and middle, and sometimes outer, middle, and inner.
If the problem is just outer, there is a good chance she could have surgery to create the visible part of the ear and open the canal if necessary. Or a bone-anchored hearing aid or implanted mechanical hearing aid might be needed--and those types of surgical hearing aids can work whether the outer ear is repaired or not. They provide much better clarity of sound compared with regular hearing aids (assuming the person is a good candidate for them).
Best of luck, and thanks for visiting!
BC