It is not noise that is upsetting her it is that while she was so sick I spent so much time in physical contact with her for weeks.
She developed a few odd behaviors from needing the special care for so long. Time and easing her out of them will work.
When Jack was one and did the rock swallow challenge (yes I gave it a name

) he was off for a few months too. Me leaving was horrific for him too.
Odd things.....my shoes with laces trigger a panic attack, any jacket except the yard coat, touching my hand bag, going near the front door, closing them out so I can mop, closing the bathroom door. Just weird crap she is reactive to.