Do you need us to translate it or not??
Yes, this is grammatically correct.
<h3>Escribe la forma correcta del verbo reflexivo.</h3><h3>- Mi madre (sentarse) en el sofá para ver la tele.</h3>
<em>Answer :</em> Mi madre <em>se sienta</em> en el sofá para ver la tele.
Explanation: In reflexive verbs, the subject that performs the action of the verb is the same that receives it. Mi madre <em>se sienta</em>.
Regreso, hope that helped!