。
Her face looks like her mother's.
Literal
She [topic-は] face [subject-が] mother [target-に] resembles.
似る ('to resemble') accepts both と and に for the comparison standard, with a soft split: と often suggests mutual resemblance ('A and B look alike'), while に leans toward one-sided ('A looks like B'). This に variant feels slightly more colloquial. The は…が split is a classic Japanese pattern for narrowing topic and comment — 'as for her, the face is what resembles her mother' — which lets only a sub-part of 彼女 (her face) carry the resemblance claim. お母さん ('mother') with the お- prefix is the everyday respectful word; 母 alone would refer to one's own mother in formal speech, while お母さん works either when speaking to children or about other people's mothers.