Babies grow the same way, and food has the same nutiritonal value regardelss of the race of the baby. What a crazy thing to think, let alone say, that race has anything to do with it!
The nutritionist at the health center I work at say that frozen veggies and fruits are often more nutritous than fresh food you buy, becuase it is frozen right after picking and then retains minerals/vitamins, whereas by the time you eat fresh veggies that sat in the market, then in your fridge, they have lost a lot of the nutrition. Unless your mother in law is growing a garden and you are eating truely fresh picked produce, she hasn't a leg to stand on.
Your baby = your say, your mother in law doesn't get a voice in what your baby eats.
Congee isn't all that great anyway, sure it is fine sometimes, but it shouldn't be the main food a 1 year old eats. They need far more texture and fibre. They should eat the same foods as an adult in smaller amounts.
The butter comments, ridiculous. Butter is milk fat, fat is what your brain is made out of. I supppose your mother in law would prefer your child drink some of that canned formula powder marketed for toddlers, it seems to be popluar among locals. The fat in that is milk fat, same as the butter. If she is so concerned about freshness does it not make sense to eat actual milk products like breast milk, cows milk, yoghurt cheese and butter, instead of a highly processed canned formula?