Before Sylar shoots Maya, she is wearing a crucifix around her neck. The next scene shows Mohinder and Sylar talking and then Sylar shoots Maya. When she is hit by the bullet, she is no longer wearing the crucifix and a black spot appears instead. When she is falls down, she is wearing the crucifix again but the black spot is still there.
When Mohinder revives Maya we see a close shot at the bullet popping out of Maya's chest. It is clear that it's an empty shell and not a real bullet.