I've just learned to smile and nod when strangers give their, ever so helpful, advice
With my mother, I just tell her all the logical reasons I pick up Kylie at the smallest sign of distress, and why I don't cram jarred foods down her throat. She didn't believe me until her nurse friend told her what a wonderful job I am doing
I called this friend and thanked her from the bottom of my heart :LOL
She loves that I use CD's so at least I don't hear about that one. I think living in Oregon is the reason I only hear positives abour CD's.
I think nodding, smiling, and changing the subject will give people the hint to back off. Most people, IME, have caught on when I do this. I had one friend (my best friend actually), who wouldn't get it. I finally snapped at her and layed it all out. She argued with me awhile and then finally stopped
I hope I never have to resort to those means again.
I hope you are able to get those around you to back off. If not, at least you know you are doing an awesome thing for your little one and Mother Earth.