Am I overreacting?

Sorry for the long post… TLDR: my husband’s grandmother watched me change my son’s diaper

I really need someone to honestly tell me if I’m overreacting right now. I’m a first time mom and I have severe postpartum anxiety. I see everyone as a threat to my son’s safety to some extent so I really need non biased opinions on this….

My husband’s grandmother met my 3 month old son for the first time today. I was already on edge because it gives me anxiety when other people hold him, I worry about them dropping him or passing their germs on to him and he still can’t fully hold his head up. Anyway things are going fine when she tells me she thinks he has a poopy diaper. I take him from her and bring him to the changing table and she follows me. I’m not the type of person that changes their baby in front of people and I don’t let just anyone change him, only myself and my husband. So she’s just standing there watching me take his clothes off and I’m trying to stall a little by pinching his cheeks and tickling his belly hoping she’ll walk away but she says “I just want to see if he pooped” (why???) so I peek in his diaper and say “nope he didn’t poop” thinking she’ll leave but she doesn’t, she waits for me to take off his diaper it’s very obvious to me she wants to see his privates. I got a horrible feeling in my stomach while changing his diaper and I tried to cover him as fast as possible… it just felt so violating. Later on my husband was changing him and she did the same thing!!!

I just don’t understand why she did this??? Why did she need to look at his privates??? Was she trying to see if he was circumcised or something??? That’s none of her business but she could’ve just asked….

I don’t know if I should bring my concerns up to my husband. That’s his grandmother I don’t want to upset him. What would you do in this situation? I really do feel like she violated my son’s privacy. I should’ve told her to get away but I’m really soft spoken and non confrontational and there were a lot of people in the house I didn’t want her to make a scene as she’s very loud. Idk… am I overreacting?