Credit: Humberto Carreno/

Suri Cruise -- who turns 4 Apr. 18 -- just can't put down the bottle.

She was spotted drinking out of one Friday in New York City, where mom Katie Holmes is shooting the crime-thriller Son of No One.

Last fall, experts told it was imperative for Holmes, 31, and husband Tom Cruise, 47, to wean their daughter off the bottle.

"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," said Dr. Jennifer Shu, a pediatrician and co-author of Food Fights. "That development comes pretty early."

Shu told Us she didn't "know why" Cruise and Holmes still allowed their daughter to drink from one. "You don't force kids to crawl when they can walk," Shu told Us.

But Dr. Harvey Karp -- a pediatrician, child development specialist and creator of the DVD and book, The Happiest Toddler on the Block -- said it isn't a huge deal.

"Sucking is normal for kids when they are tired or bored," he told Us, "as long as kids aren't keeping the bottle in their mouths for hours."

Tell Us: Should Suri still be using a bottle?