Who were the kids in Ziva's photograph?

They never really answered it; however, your guess is probably correct considering that Eli David had the picture on his work desk, and who else would he have in a picture but his children? Also, they are all about the correct ages: to me, Ziva looks about ten or eleven, Ari twelve or thirteen, and Tali about four. Tali died when she was sixteen, so Ziva would be twenty-twoish- a correct age considering she said she was already Mossad at the time. :D

I know for sure that this is an old photo of Cote and her younger siblings, they just put another boy in Panchos (Cotes brother) place. I guess they mean to be Ari, Ziva and Tali. As for Ari being way older than Ziva- this wouldn't be the first time they messed up with things like age (difference) and trivia
here's the original photo:

Agree with your theory, this photo looks pretty old. Although they can doa lot of things with photoshop nowadays.

Have you heard about Ziva's new movie? lastritesfilm.com

I thought it was Tali(Ziva's sister who got blown up), Ziva and Ari as well.

In the show it's her brother Ari and her little sister Tali. In real life it's her brother and sister they used a real pic from her cote de pablo's childhood!!! :)

The producers want us to believe it's Ari, Ziva and Tali. However, we know Ziva was born in 1982 (The Inside Man on her application to become an NCIS agent) and Ari was born in 1969 (Reveille). This means the boy in the photo cannot be Ari. The boy is about 12 years old and Ziva about 10. Ari would be 23 years old when Ziva was 10!

I like to think it's actually Rivkin. Boyhood friend of the David's. Taken in by Eli after his own parents were killed on a Mossad mission. Turns rouge just like Ari. Just a story!

True fact: the girls in the photo? That is actually Cote de Pablo and her real life younger sister. Have no idea who the boy is. I do know that Doug Reilly had to stretch him out to make him appear older than he actually is.

It has to be Tali, her younger sister, who died at 16, Ari, her half-brother, and Ziva herself.