Sally was a cashier at a grocery store that Kevin McCallister visited when he was there by himself.
When she observed Kevin walking up and placing items on the conveyor belt, she was more suspicious than concerned that he would be there by himself, but checked him out anyway. When Kevin casually asked if the microwave dinners were any good, she said she didn't know, and he replied with "I'll give 'em a whirl" while looking through a magazine he had found on the rack, and she smiled (as though impressed with his wanting to try something new).
Finally, she asked him if he was there by himself. Kevin dismissed her question calmly, prompting her to quiz him on where his mom, dad, and siblings were, where he gives her false answers. She then asked him where he lived, but he refused to tell her. When she asked why, he replied in a serious tone, "Because you're a stranger."
- In the Home Alone trailer at the store scene, the store manager is questioning Kevin, not the cashier herself.