Amma has been posting the baby's photos on her public profile. How do I raise it?

Amma lives with us and does most of the daytime care for our son, who is a few months old. We could not manage without her, and that is not an exaggeration. Last week a colleague mentioned she had seen him in 'your mother's posts'. Turns out amma has been putting up a photo almost every day, with his name, sometimes with our building gate in the background. Her profile is public. A few hundred followers, most of whom I have never heard of. My partner and I had agreed we wouldn't post him anywhere. We just never told amma, because it didn't occur to us that she would. How do I raise it with her so it doesn't land as criticism of the person who is up with him at 6 every morning?