I doubt she will kill him. most she can do is leave the character like neo in matrix.
Like Neo , Harry is a character larger life which if killed it will be very difficult to give an explanation to its fan.
I hope and think that she wont kill harry, worse I guess she will keep the reader's hanging on the fate and future of harry, like neo's fate.
Ron certainly wont die. But she killed Padfoot, so she can kill anyone. But Ron is the only comic relief in the books she cant bump him off.
Jammy.