From Examiner.com
Some fans noticed that Tyreese had some sort of carrier on his back.
Inside it resembled a baby, although the shot of it wasn't close up.
This caused some confusion with fans on whether baby Judith was dead
or alive.
On "The Talking Dead," the subject of baby Judith was brought up and
it was confirmed that the infant is alive and well. She was in the
carrier that was on Tyreese's back.
If she had died, it would make sense why they wouldn't show her at
all. The death of two children is hard enough for one episode,
although one of them was a danger to survivors everywhere. But seeing
the death of a baby would be too much for many viewers. Not only that,
but fans are looking forward to Rick and Carl finding out that Judy is
alive after all.
From a different Examiner.com article referencing the Talking Dead chat show:
On March 16, "The Talking Dead" confirmed the fate of the baby.
They didn't show Judith at the end of the episode when Carol and
Tyreese were walking away, but if you paid attention you could tell
she was there. He was wearing a yellow pouch on his back. Paying
attention to it you could tell that it was Judith and could see her
head with a hood on it.
On "The Talking Dead," it was confirmed that yes that was Judith on
his back.