。
She tells everyone she meets the sad story of her life.
Literal
She [topic-は] meet person all [to-に] herself [of-の] unhappy life-story [object-を] does.
Two pieces work together: a noun-modifying clause and a useful collocation. 会う人すべて = 'every person (whom she) meets,' built by the bare verb 会う sitting in front of 人 with すべて ('all') tacked on the end. And 身の上話 ('life story, personal-circumstances talk') is the set phrase Japanese reaches for when describing someone's monologue about their own background, usually with a hint that the listener is hearing more than they bargained for. 不幸な ('unhappy, ill-fated') sets the tone — these are the stories of how she's had a hard time of it.