It is only natural for a new mom to feel protective over her baby.

When somebody has put all that effort into bringing a child into the world and dealt with wild hormonal fluctuations on top of that, it is understandable that they may have some strong boundaries in the early stages of parenting (and as the kid grows up, too). 

A lot of the time, this is sensible; there are plenty of things that are inappropriate or downright dangerous to expose an infant to, and the mothering instinct is there to shield them from that. However, it is also not uncommon for friends and family to accuse moms of going overboard with their protectiveness. 

Among the many challenges of early parenthood is the need to prove how a parent feels about how other people interact with their baby is not something to be dismissed. Unfortunately, there are plenty who disregard this.