She suppresses the urge to run. A rising panic fills her. Her mind feels like a room full of propane where one wrong thought might light a spark. Her eyes shift back and forth from the distance to the flickering, ever-changing wrongness of her immediate surroundings.
'I'm on drugs', she realizes. 'I must be on drugs.'
Wait, how? She just went for a walk around town, with a little break for a pumpkin spice latte at that cute coffee bar on 34th street. It had the cute couches and the cute waiter, and the cute ... uuuhm, do people spike each other's coffee nowadays?
She shakes her head. 'This is paranoid.', she thinks.
So maybe she is unwell? Is this one of those things that can happen if you have an aneurysm or a brain tumor?
In either case, staying calm is important - accept that things may seem different from how they truly are. If she's on drugs, she can give herself a bad trip. If she is having medical issues, then freaking out will make it worse.
She could also be having a psychotic break down. How do those even work? How can she tell if she's hallucinating?
Triangulate. That's it. Triangulate the information. This is just a puzzle.
Logically, if she keeps going, she should soon reach the edge of the park and hit the enclosing fence. If however, she is not in the park after all, then she should encounter a building or street. If none of that works because this is all in her head then she won't be able to perceive fences, streets or buildings. However, in that case her body should start colliding with objects that disagree with her mind's new creative direction for reality.
'And that makes *not running* pretty important.'
Also, this place is kind of beautiful in an eerie and foreboding way. Maybe she can turn this rising panic in to something beautiful. This experience will end and the world will become mundane again. Let's carefully keep walking forward, carefully keep picking a path past the brambles and thorns, and carefully keep focused on the more visually cooperative plants in the distance.
Breath in, breath out ... She's got this.
A few more steps, and a few more breaths, and she finds herself softly humming "Rockabye baby" as her fingers gently twirl around the thorn bushes in passing.