How to address grandparents sending photos

Not sure if I'm overreacting and just need to pick my battles with this one. My mum doesn't live near us, I keep her updated with photos and videos. She doesn't post them on social media but she mentioned she sends them to her friends. I know her - she's a chronic oversharer with no filter, we could not trust her with any information growing up. She thinks she's getting better but I'm not sure.

I asked her to not send on anything that I put in a specific chat (framed it as 'these are special and just for our family', but really these are the only pics I send) and I thought she took it well. A friend of hers/mine has just text me and said among other things she's getting pics of my son every week.

Everything she does is pretty triggering to me so I'm not sure if I'm overreacting, but it just seems really weird and unnecessary to me to be regularly sending pics to people that my son doesn't have a relationship with and will probably never meet, unprompted. Any tips for addressing this with her?

Edited to clarify: I don't mind her showing friends pics occasionally, but strangers having dozens of photos of my son on their phones makes me uncomfortable. I have no idea what's being shared and to who and surely I have a responsibility to try to protect his privacy somewhat until he can give consent? This feels really different than looking at a photo album together, she loves him and is so proud of him and I would have zero issue with her showing friends physical photos, or honestly even sending out a pic or two occasionally. I think I'm concerned with the volume and lack of discernment about what's appropriate information to share to whom.