Sentence:  I feel certain, looking back, that we must have walked through someone's <WSD>family grouping</WSD> at the exact moment the shutter closed; surely, some father wielding a video camera must have captured us somewhere, climbing into a teacup or reading the gravestones outside the Haunted Mansion, while his children, fidgety and drunk with excitement, ran around people's legs in the foreground. 
Meaning of the word marked with <WSD> tags:  A group of family members who are posed together.