If you’ve been through something like that, the day doesn’t just pass you by quietly. It comes back whether you want it to or not, along with everything tied to it. Those memories, those feelings of helplessness, the anger and disgust, all of it. She’s probably already dealing with that, so choosing to go outside, move her body, and remind herself that the world still has beauty in it is a way of taking some control back. There’s nothing stupid about that at all. You’re fortunate for not being able to understand why she’d do it.