。
She is a very nice person.
Literal
She [topic-は] very good person is.
About as bare-bones a polite-form sentence as you'll find: topic + adverb + adjective + noun + copula. いい人 ('good person') is high-praise shorthand — when said sincerely, it carries warmth; when said dismissively about a romantic prospect, it can land as 'nice but not for me' (the dreaded いい人どまり, 'stuck at just being a nice person'). Tone disambiguates.