A common assumption is that each word might be shifted by a certain number in the alphabet (Caesar cipher) or encoded with a simple substitution.
So here it is:
At the station, frozen and silent, she found a metal box under floor panel 2, row 3, slot 6. Inside: a photograph of a woman who looked exactly like her, dated next week. thmyl fysbwk layt andrwyd 2.3.6
She grabbed her coat. Outside, snow swallowed the gravel road. A common assumption is that each word might
But if it's Atbash (A↔Z, B↔Y, etc.): t (20) ↔ g (7), h (8) ↔ s (19), m (13) ↔ n (14), y (25) ↔ b (2), l (12) ↔ o (15) → gsnbo — no. Given the puzzle-like nature and the numbers 2.3.6 , it might be a book cipher — page 2, line 3, word 6 of some text. Or a software version "Andrwyd 2.3.6" (Android misspelled?). She grabbed her coat
Given the last part "andrwyd 2.3.6" , that looks like a version number or coordinates. "andrwyd" could be "and ruwyd" or "and rwyd" ? rwyd → rwyd might be "rwyd" as in "rywd" ? Could be Welsh: "and rwyd" (and net?) but "thmyl" doesn't fit Welsh easily.