Menopause or mental issue

My mother is in early 50s. In the last 2 years, her moods have become more and more erratic and ridiculous. Sometimes I feel that she is behaving like a teenager with PMS. My #2 was born in feb, and she didn't wanna come and see him. Her reason was she thinks he's a very unlucky baby, born and caused the whole world to suffer covid. Seriously??? There were other things she said which made me boil, e.g. my children also not follow her surname so she don't. She also lied to my husband that I sent her insulting messages which I didn't. How is "thanks" insulting? Since I was young, I see her as a compulsive liar who can really lie through her teeth. I don't know if this is menopause or mental problem. She has been the nasty one but she always go around telling people i'm the one doing what she did to me. Does menopause break up family ties like this?