PN.
The TV programme said he wasn't, as does the Guardian article
At the time of the assassination, at near point-blank range by a teenage gunman, described later as "the shot heard around the world", it was reported that Franz Ferdinand owned but was not wearing body armour.
However it was tenuous to say it would have protected him, she might have survived though.
He fired twice into the car, hitting Ferdinand in the neck and Sophie in the abdomen. Both died within the hour.