I guess this is just the next thing on the list. Ugh!

edited...

Found this page on hyperacusis on the website of the ENT academy:

http://www.entnet.org/content/hyperacusis-increased-sensitivity-everyday-sounds

It notes that hypersensitivity to sound is usually an auditory processing disorder, not purely sensory in nature. It also notes that some individuals with hearing loss also have low tolerance to loud sounds, with a narrow range of tolerable volumes at certain frequencies. (See "recruitment") Sound sensitivity is also associated with a number of other conditions, including migraines.

And a random internet article about recruitment. Can't vouch for it's accuracy, but FWIW, it's cited on a number of other pages:

http://hearinglosshelp.com/blog/recruitment-from-hearing-loss-explained/

No help but I also have sound hypersensitivity and now some heading loss as well although I don't know whether they are related.

Missed this the first time around and not sure how relevant it is to her particular sensitivities/hearing loss but I'll share in case it helps.

A few years ago I ruptured an eardrum which basically meant I was deaf in one ear while it healed (it took a couple months over which my hearing improved slowly). The first few weeks when I had no hearing were quite an experience though. Any situation where more than one person was talking was impossible for me and even slight background noise made hearing a person very challenging. We went to a small dinner party a couple weeks in and I had to leave, I couldn't hold a conversation and I quickly had a pounding headache. Having experienced that I wouldn't be surprised if a person with hearing loss would avoid noise, especially if they were expected to listen or have conversations.