Biting my tongue

The pickle is lucky enough to have 2 cousins who are 6 months younger than him. One being my middle brothers boy and they other being D's sisters boy. D's sister lives in South Africa and has come over to the states for a visit bringing her son Seth with her, followed by her husband a few days later. D's sister and I have gotten along very well in the past as long as we don't discuss politics or religion. This past weekend I have come to realize that parenting is on this list as well. The problem is I'm just not sure that I can or should keep my mouth shut. When Erin and Seth came to our house for a visit she asked if she could feed him in the high chair. Of course! When she put him in the chair she explained that she was teaching him "high chair manners." I hadn't heard of such a thing. High chair manners apparently state that your 6 month old child should sit with their hands on the high chair tray and not lift them. If they reach for the spoon you push their hands back down and say 'Where do our hands go?" I was slightly appalled at this thinking of how it is sort of a developmental step for babies to reach for things and to begin picking things up. Later in the evening D was holding Seth and Seth was holding D's thumb and had a little bit of the webbing between D's thumb and pointer finger between his thumb and pointer. Erin then scolded "Sethy" "Don't pinch! We don't pinch Sethy!" while trying to pry his had off of D's thumb. D was telling her that he wasn't pinching him and that it was fine. She told D that "No, he was pinching and he doesn't need to pinch."

We then went to visit them at D's parents house last weekend. D set the pickle on the floor next to Seth and handed him a toy. Seth reached for the toy and Erin pushed his hand away and said "Don't grab Sethy." D told her not to worry about it, that it wasn't personal, just what babies do. Erin replied "Well, he is being grabby and he doesn't need to be grabby." Later in the day we were shown how she is trying to teach Seth how to crawl, by placing him on his belly and moving his hands and knees for him, all the while Seth was crying.

I feel so bad for little Seth, I'm just not sure if something should be said to Erin, and if so what do you say? I feel that Seth is not allowed to be the baby that he is, and is not being allowed to explore the world or find out how things work. I did make a comment while she was out of the room to her parents and it was clear that they thought the high chair manners was a bit much, and possibly detrimental toward teaching him to feed himself, but if they aren't going to say anything should someone else? I have tried to start parenting discussions with her but it is very clear that she has no interest in any way but her own. I feel that if I mentioned something to her it would only push her away. D has stated that he finds the behavior to not ring right for him either, so maybe the best thing would be for him to start a discussion with her. I just feel bad for Seth.