On Wednesday, Katie Holmes was photographed bottle-feeding daughter Suri on the New York set of her new movie, The Romantics.

Should the girl, 3, still be hitting the bottle?

No, experts say.

"She should have been weaned off the bottle by the time she was one year old," Dr. Jennifer Shu, a pediatrician and co-author of Food Fights, tells "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 or a cup with straw. That development comes pretty early."

So what gives?

Shu says she doesn't "know why" Tom Cruise and Katie still allow the girl to use a bottle. "You don't force kids to crawl when they can walk," Shu tells Us.

But Dr. Harvey Karp -- a pediatrician, child development specialist and creator of the DVD and book, The Happiest Toddler on the Block -- doesn't think it's such a big deal.

"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" he tells Us, adding that it may serve as an emotional security device. "Thumb-sucking is more damaging."

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But Shu tells Us that if Suri is using the bottle out of comfort, her parents should "transition her to a different security object that doesn't cause cavities," such as a blanket or a Teddy bear.

Or, perhaps, some high-heel shoes?