。
She should listen to other people more.
Literal
[topic-は] more others [genitive-の] say [nominalizer-こと-を] listen should.
他人 ('others, other people') as a noun frames the subject of the embedded verb — 他人の言うこと literally 'the thing(s) that others say.' The genitive の here functions as the relative-clause subject marker (= 他人が言うこと). 言うこと ('what someone says') is one of the most common nominalized verb-phrases in Japanese, with こと packaging the verbal content into a graspable object. ~べきだ ('should') frames the recommended behavior.