This is really about two differing views on bringing up children colliding with a bang that set of a family row with anger and hurt feelings on both sides.
We have all been there and done that, haven't we?
I drank coffee from the age of two, with plenty of milk in it, and no-one in Scotland in 1953 thought that at all odd. Or if they did, they kept their opinions to themselves.
In Denmark at the same time, coffee was considered EXTREMELY HARMFUL to children under the age of 14, although they were allowed to drink tea. As recently as 2001 the same view was held in Poland, as I found out when helping run a holiday camp in Denmark for Polish orphans.
Any grandparent who ignores a parent's wishes regarding the upbringing of their child is out of line in my opinion, and so is a husband who is not prepared to stick up for his wife's right to decide, although it is fair enough if he criticised her manner of expressing herself to his mother.
A husband and wife who don't agree on any point regarding their children's upbringing should sort the matter out in private and present a united front to the children and both sets of grandparents, plus uncles, aunts and busybodies.