She’s been to hell. She was there for two years which is also the equivalent of 240 years hell time. So now that she’s back, she going to be bitter towards most people, regardless of whether or not she was friends with them before she died.
She’s also going to be rather blunt about things, calling them like she sees them instead of holding back. Her emotional barrier was blown away so things are kind of out of wack. She doesn’t really care if she hurts your feelings
That doesn’t mean she won’t have moments of normalcy. She is still Jo, but the old Jo is buried deep and will take a while to get her closer to the surface.