Respect Yusuf's wishes to interpet for Maha, and kindly ask the interpreter to leave.
Whilst Yusuf may be capable of interpeting for Maha, it is not ideal for him to do so. He may not know accurate translations for medical terminology or may change the information to protect Maha. Additionally, by interpreting, Yusef may be less able to focus on providing support to Maha during the consultation.