A crazy woman is claiming my baby

Ellie • Arthur Benjamin due July 3rd, 2020💙

So I’m about 7 weeks pregnant, and most of the people I work with know. A woman who just started 2 weeks ago has decided to claim my child. She told me that her daughter won’t give her a grandchild (no surprise to me), and since my mom lives another state over (literally only 1.5hrs away) that my baby is her grandchild. She never asked me, and it doesn’t seem like a joke. She just demanded this be the case, and has even started telling other coworkers that she’s the grandmother! I’ve explicitly told her no, and that I’m not okay with that but she ignores me. It’s honestly kind of terrifying. I feel like she’s the type of woman who would show up to the hospital at my birth (regardless of me giving her that info) and steal my baby. Is there anyway I can get it across to this woman that she will have nothing to do with this child?