Sansa's decision to stay in King's Landing instead of escaping with the Hound was one of those pivotal moments that really showed her growth—or rather, her survival instincts kicking in. At that point, she'd been through so much manipulation and betrayal that trusting anyone, even someone like Sandor Clegane who had moments of gruff kindness, felt impossible. The Hound wasn’t exactly a knight in shining armor; he was volatile, and his offer came during sheer chaos. Sansa had learned the hard way that impulsive choices got people killed in Westeros. Staying put, as awful as it was, might’ve felt like the lesser risk. Plus, she still held onto some naive hope that the Lannisters or her family’s allies might save her. It’s heartbreaking in hindsight, but it makes sense for her character at the time.
Looking back, it’s wild how much this moment foreshadowed her later arc. Sansa’s refusal to flee was almost a metaphor for her clinging to the idea of 'Lady Stark'—proper, poised, waiting for rescue. It wasn’t until much later, after more trauma, that she realized survival sometimes meant getting your hands dirty. The Hand represented a rougher path, one she wasn’t ready for yet. Funny how her eventual reunion with him in 'A Feast for Crows' (the books) hints at what could’ve been, but by then, she’d already outgrown needing a savior.