His life brightened up when his daughter came home.
Literal
Daughter [subject-が] returned-come [because-ので] his [possessive-の] life [subject-が] bright became.
明るくなる ('become bright') used metaphorically for 'cheer up, become happier.' Double clause linked by ので, with an embedded subject (娘が) and a different topic/subject in the main clause (彼の生活が).