Sera

Leaving the village behind her, she then steps off the path, walking into the woods. She leaps up the trees with ease, moving from one to another in a series of swift movements that doesn't create any noise. Using a skill of hers, her skin begins to match with the decor, blending in with the trees.
It would take perhaps 20 minutes of heading toward Vestris before she begins to feel patrols. 
(Pulse.)

Over a massive radius, she can feel all living pulses. From humanoids to creates and even small animals like birds. It doesn't work as well with insects. For the best, else the amount of data she'd receive would be unbearable. There's 16 of them at various different areas, in squads of 4. The frequency and numbers of patrols have drastically increased. There use to be one or two patrols of up to two guards. She moves closer, sneaking in, completely undetected.
(Vocal sense.)

Their hearing sense improves drastically, the sound waves produced by their voices having an easier way reaching her ears.
"When are we going back?"
"When the sun starts to set."
"That's such a long time. I'm bored. Nobody is passing through here. Glarion isn't going to raid us."
"Our officials told us Glarion might raid at any given time. Spies could be listening on us at any given point. We're here for a reason."
"That sounds like paranoia."

It might sound like paranoia, but your friend isn't wrong. I'm right here, listening to you. 
Glarion? Raiding Vestris? That hasn't been ever mentioned at any point in time.
Even Saito hasn't heard anything of the sort. Or maybe he has and he's hiding it?
She could ask him and listen to his heart rate, see if he's lying.

Is that how they're trying to justify going to war with Glarion? But spreading misinformation about the other kingdom seeking war? She bites her lip, hatred boiling with herself.
If only she could do something about it right now. If it was up to her, she'd kill every single one of those guards right now. But she can't involve herself yet. Not alone.
She moves further in, seeking to learn more information.
The other patrols wouldn't really mention anything worthwhile, merely doing small talk or walking in completely silence. Detecting a large quantity of living beings far ahead, she looks up, trying to perceive them between through the trees. There's maybe 40 of them in there. Is it a village?
No, they're all focused in a small radius. It's likely more of a military gathering. She'll have to report that. 

She should assert the threat for certain. Telling her group that it's "maybe" a military gathering won't fly too well. She slows her pace down, carefully going deeper into Vestris's territory.
Once the camp in eyesight, she very slowly takes cover, taking in what she's saying.
This is probably where they make rounds for the border. There's an unusual lot of them.
While some of them are indeed guards, most of them bear military issued armour.
Her eyes lock onto one man in particular. That's one of Vestris's champions. Here? At the border?
The village is truly facing a possible invasion.
Using one of her skills, she vanishes, teleporting back where she was a while ago.

The moment she vanishes, Vestris's champion immediately stop, glaring over at the tree she just stood at.
"Is anything the matter sir?"
"... No. Resume activities."

Without alerting anyone else, she crosses the border, returning to their wagon in complete silence.