As such, the "at the same time" part of it is set it stone based on her previous day's hike because it has already happened that she passed each point of the trail at a specific time. If this were a math story problem with the info of "she maintains the exact same pace the entire time she's hiking and doesn't take any rest breaks," then you'd be exactly right. Since no human being hikes that way, it's highly unlikely that she'd actually be at the exact same place at the exact same time both days.