。
She has the regal features of a princess.
Literal
[topic-は] just-as princess [genitive-の][as-ように] noble face-features [object-を] is-doing.
顔立ち ('facial features, face structure') refers to the underlying bone-structure-and-arrangement quality of a face — distinct from the transient 表情 and the molded 顔つき. 高貴 ('noble, high-class, refined') is a Sino-Japanese adjective with weighty literary register; daily speech might use 上品 ('elegant, refined') for similar territory. 王女 ('princess, daughter of a king') is the precise term — Japan's traditional 内親王 (naishinnō) for imperial princesses is more formal still. The whole sentence is purely complimentary, the kind of admiring observation in fairy-tale or fashion-magazine register.