Completely uncalled for!!!

I was at my MIL house the other day visiting so they can see their grand daughter and we have her on formula as a supplement with breast feeding cause I don’t produce enough:

And my daughter was crying and this women looks me dead set in the eyes and goes

“ why is she crying I can’t tell what a formula baby wants. Cause all mine never had that toxic ness in them.”

In that moment I wanted to back hand her across the face so bad because fed is best but she keeps making constant jabs whenever I’m over