Sucking is quite normal for little kids, but in time they have to outgrow the habit as it can affect their overall behavior, according to various medical studies. But it seems like Katie Holmes hasn’t heard of that reminder-given that she was spotted feeding daughter Suri with a bottle filled with milk.

Suri was found drinking her milk from the bottle during the set of her mother’s upcoming movie, “The Romantics.” This alarmed experts, saying that the three-year old toddler “should have been weaned off the bottle by the time she turned one.”

According to pediatrician Dr. Jennifer Shu, “by the time kids are nine months old, they have the physical development and mouth coordination necessary to be able to drink out of a sippy cup with straw. That development comes pretty early.”

Another pediatrician, Dr. Harvey Karp, however, is not totally bothered by the issue.

“Sucking is normal for kids when they are tired or bored-as long as kids aren’t keeping the bottle in their mouths for hours. Thumb-sucking is more damaging.”