I am sorry to hear that your pup Daisy Mae seems to be losing her hearing ability and I understand how concerned you must be.
There are several reasons for dogs to lose their hearing and whether anything can be done depends upon the cause.
How long has it been since she was treated for an ear infection?
There are some antibiotics that can cause damage to the nerves that transmit sound information to the brain. Gentamicin is one of these antibiotics, but it also has excellent efficacy against the common bacteria that cause ear infections, so it is in many antibiotic drops formulated for ear infections. Generally if the infection is limited to the external ear canal and the tympanic membrane (ear drum) is intact we can use it safely in the ear. If the ear drum ruptures though damage to the nerves can result, and cause deafness. In many cases if the medication is withdrawn the nerves recover and the dog can hear again. But unfortunately in some cases it is permanent.
It is also possible that the ear infections themselves over time damaged the nerves in her ears leading to deafness. That may or may not be reversible, but in most cases is not.
Many dogs with bad ear infections get fluid in the middle ear in response to the inflammation from infection itself and that will also cause loss of hearing. If the infection is resolved and the fluid goes away then the dog will be able to hear again.
It is also possible with a severe infection to have so much swelling of the ear canal itself and waxy debris build-up that the dog cannot hear. Once we resolve the swelling and remove the waxy build-up these dogs can hear again.
A mass or polyp in the ear may have precipitated the infection and led to your pup's deafness. In these cases if the mass or polyp is removed they may be able to hear again, unless the nerves were irreparably damaged by the mass or pressure from the mass.
Finally as dogs age they tend to lose their hearing, this is very, very common. Because they have such great hearing compared to us we may not notice it until they are almost completely deaf. This may have been something that has been slowly coming and the ear infections and medications that were used have nothing to do with her deafness or it may have been that she had a little hearing left and the ear infection and swelling in the canal led to more noticeable loss. Dogs are great at reading body language and facial expressions of their owners so they compensate quite well and it is difficult to pick up on hearing loss until they are almost completely deaf.
All you can do for her now is make sure any infection is cleared, waxy debris is removed, and that there isn't a middle ear infection or residual fluid in her inner ear or a mass in her ear that is interfering with her hearing.
If there was a recent infection but the ear is cleared up now and there are no other complicating factors then give her time and see what happens.
Please let me know of you have any further questions.