I think it is OK to report on the effects you observe on the baby. Things like: "first 150ml went in easily, additional 50 huge struggle, bigger puke than on smaller bottle" is not a criticism, it's a fact.
"Still gagging with solids" is likewise. "Cried for 40 minutes until rocked" is also a fact.
Mum may actually not be aware of the consequences of some of the changes.

It's hard to remember that most kids of the 1950's turned in to happy, functioning adults too!