Is it permissible for a younger brother to force his older sister to stop watching songs and TV series under the pretext of enjoining what is right and forbidding what is wrong, and what is the Shar’i (Islamic legal) stance on this action and the sister’s behavior?

Listening to music and watching TV series that contain objectionable content is forbidden by Islamic law. It is an Islamic duty for the brother to object to his sister, as this is enjoining good and forbidding evil. This should be done with gentleness and leniency as long as it is effective; otherwise, he should resort to severity and admonishment. Abandonment is permissible if it is likely to be beneficial. The young age of the brother does not exempt him from this duty. As for the sister asking the question, she should support her brother, assist him, and advise him, and she should also advise her other sister to abandon the objectionable acts.