Between A Rock And A Hard Place.

She wouldn't believe him even if she put aside his recent fights with Primogenitors. She chose the direction that she thought was safe. She chose a boundary of her territory that is completely sealed and hardened earth. There was no tunnel in that area so no one should be there. 

Ghouls could be anywhere outside her territory. But they are most likely to be around other vampires. All of the Vampires were in the pathways that led to her territory. So it should be unlikely that Ghouls would be within the walls. She was right. There were no ghouls there. But she was nabbed as soon as she left her territory.