。
She's a girl like an angel.
Literal
She [topic-は] angel [like-のような] girl is.
~のような is the prenominal form of ~のように — it modifies the following noun 少女 rather than a verb or adjective. 天使のような少女 = 'an angel-like girl.' Compare: ~のように修飾する (modifies a verb/adjective) vs. ~のような＋名詞 (modifies a noun). This distinction between adverbial and adnominal forms is important for placing similes correctly in a sentence.