。
She makes a living as a teacher.
Literal
She [topic-は] teacher [as-として] livelihood [object-を] is-making-up.
として ('as, in the capacity of') marks the role one occupies — slightly more formal and explicit than the alternative 教師をして construction (profession + を + する). として often appears in CVs, formal introductions, and any context where the 'role' aspect is prominent. The two sentences are nearly synonymous, but 教師として feels more lapidary and formal than 教師をして.