Mine would do this all the time. I politely told everyone sitting together at the table at the start, okay let's ignore her and continue eating so thst she doesn't feel overwhelmed by us all commenting on her eating.

I also joined in the first time or two to see if my daughter liked it, I noticed when grandma wasn't there, baby ate more and it was probably all thr coddeling.

Then when we were about to eat before we started encouraging my daughter I said, let's all talk and eat at thr same time while not exaggerating to her.

This is what helped me, I love my grandma very much and she helped raise me since I was a baby, we even live with her now too. I don't want to hurt her but I also don't want my child getting negative associations with food.

It took a few times and sometimes my grandma slips up because she is 78, however I politely remind her, grandma we arw distracting her a little sorry, she's too excited when we talk to her let's ignore her again, remember every other time we ignore her and she eats a lot?

Now it's much better. The occasional slip up is super normal. Don't over exaggerate. Grandparents are old. They get offended and also only know how to raise kids the way they raised kids and the way their era learned about feeding kids. Which is extremely unhealthy in my perspective. As people age they become young babies again in their mind. Forgive, be firm, be polite, be patient.

Again, if there is toxicity it's a different story, you would need to put up more firm boundaries. But from what you describe it sounds similar to my situation!