。
She is trying to cut down on her expenses.
Literal
She [topic-は] her own expenses [object-を] reduce [try-to-ようとしている].
~ようとする ('to try to do X / to be about to do X') uses the volitional form + と + する to mark an attempt or imminent action. With ~ている, the construction ~ようとしている describes ongoing effort — 'is currently trying to.' 経費を減らす ('to reduce expenses') is a common business and personal-finance collocation. 経費 specifically refers to expenses or operating costs, distinct from 費用 ('cost in general') or 出費 ('expenditures').