Weird movement

So my mom told me tonight that she can feel movement like a baby is kicking and moving to the other side of her stomach. First I laughed and joked because she hasn't been sexually active since I was 11 years before her and my ex step dad broke up. And she is going through menopause and she is going to be 50 this year. So I want to know and more curious of what it can be? And has this happened to you. Also she gets a lot of uti's and she doesn't go to doctor but once a year and my grandma past away from uterus cancer at 60.