Crowdsourcing "F"

Following the railroad track with her eyes, she searched for any type of movement.  When she could see no further, she decided to slowly push herself up to look through the grass. The only sound that could be heard was the wind, and the slow but stressed breathing of her "troops". 

Scanning the surrounding area, she noticed in the distance behind them, a dark feature standing in the trees.  She knew it couldn't have been a zombie.  If it had, the zombie would have attacked them by now.

Motioning to her troops to crawl off the tracks, she slowly stood up waving to the shadow.
"Hey!  You in the trees!"  The shadow inched further into the trees, but she heard a response.  Was that the same voice she heard earlier high up in the tree informing them about a corn field?