。
She's a trustworthy person.
Literal
She [topic-は] can-be-trusted person is.
信頼できる (しんらいできる) is the potential form of 信頼する ('to trust'), used as a pre-noun modifier meaning 'trustworthy, reliable.' This pattern — potential form as adjective — is productive: 食べられる ('edible'), 頼りになれる ('dependable'). The resulting expression functions like an adjective modifying 人.