Is my religious mother mentally ok?

This question is serious and PLEASE I want no one preaching to me. I've been atheist since I was in 6th grade.I'm already in 10th. And it's not that I don't believe in God, it's that I KNOW there is NO God and I will never in my life believe in such false believes. Ok, so my mom talk's from morning till night about the end of the world and about everything, from a video game to tv, being a demon to be exorcised. And I mean it. Just now my bro typed " girls " on google, she caught him and supposedly exorcised him. My bro is atheist too so he was extremely pissed off of how stupid my mom is. He didn't even pay attention to the nonsense she spoke of. I asked him and he honestly tells me he wasn't watching any he was just staring at pictures of woman to learn to draw better and I know him extremely well, his not lying about it. This isn't the only time ANYTHING that happens she is already exorcising it, she always talks about earthquakes, since I was little she says EVERY YEAR, that this year will be the "end of the world" and that an earthquake will fall and explode the world. There was also one time she suspected I was a (which I am) because of how I dress and told me if I dared be a she would drag me to church and "exorcise" my demon. She is not abusive, just in case, she does respect us and has never crossed the line. She is the best mother I can ever have and I love her but I can't help but say I completely HATE HER when she starts exaggerating all the religious beliefs. She spends all day starring at religious forums to supposed people that prophetical things. She thinks that there are devils hidden in between humans, that cutting your hair will send you to hell, that music will sent you to hell, she believes that to enter heaven she has to pray 24/7. The only thing she talks about is god, hell, earthquake and death. Ok, so is my mom sane. Does she have a problem? I understand it's ok to be religious, but there a limit to things! Do normal religious people do this type of stuff? She really barely talks about anything else but God! She is so shallow and blind! It honestly disappointing me my mother is like this. I talked to my step-mother, who is a nurse, and she tells me she might have health problems with over obsession, my uncle who is a professional doctor says the same and that she needs help, so does my police aunt...and I repeat she is a great mother, and a great human being and does anything for our well being, I am just worried about her and since I am atheist I don't know if normal religious people are like this or if she is to obsessed with this.