I’m think there is no need to rewrite, revoice or delete Kaevee. This character is well thought out, and I think she’s earned the right to life in TSLRCM. And no matter that someone doesn’t like her.
About the voice: when I first time heard it, I thought that now Kaevee will cry. And it is not surprising, considering that I had just killed her pets! After that her voice become a little stronger—she’s clearly beginning to calm down. It’s no wonder she has such a voice—just recall a voice of crying children. So I think that next time we met her, her voice will be better.
I wrote in my pages, that we could at least have it boarding the Ebon Hawk. She could have been feeding, bathing, dressing and rebuild her mental health before being released into the wild (or stay in the Ebon Hawk) a bit like the little girl thief in Kotor 1.
It would be nice if we could recruit her instead of Disciple (if we playing as male character, of cource).