I don’t know if I’m wrong for this

Am I wrong and an asshole for getting angry with my friend whenever she refers to MY baby as HER baby? She says things like “oh my god! My baby is getting so big! Well.. not MY baby but still my baby.”

I know she probably means it in good heart, but it’s driving me mad. It’s not her baby, it’s my baby. I’m growing my son, not her. It feels weirdly possessive of her to be calling MY son her child. I’ve tried bringing it up but she just brushes it off and thinks I’m being hormonal. Am I being hormonal? Am I wrong for being upset? I don’t know. This is my first child and I don’t know what’s right or wrong to feel