Often AP's get tons of questions and concerns, even mocking and belittling because they are choosing a much different path then their parents and grandparents did.
Is the EBF (Exclusively Breast Feeding) baby getting enough to eat?
Aren't you gonna suffocate the bedsharing baby?
That baby will never learn to walk of you don't stop wearing him in that sling.
If you don't let me baby sit that child will never learn independence.
If you don't...
It goes on, the constant doubt. The constant challenges.
Honestly how you handle these questions depends on the intent of the questioner, the kind of relationship you have and want to continue to have with that person.
If the intent is to challenge and badger you then simply say "my baby, my way." You can finish with a "I've done my research and talked to her doctor, thank you but I need no other opinions isn't he matter."
If the questioner is truly uneducated, confused, but open to learning then either sit down and educate them, give them a book, send them links.
Most of the time people are just out of the loop, grand parents haven't paid attention in many years about what is going on in baby care currently and simply need to bu updated. Some will never be open to a new way, their kid turned out just fine and you are I silting them by choosing different then they did.
(((Hugs))) it is hard having parents not agree with you, my own parents do not agree with my parenting choices, but we have learned a mutual respect over time. They only comment when they truly want to know. And leave it be when they disagree.