-Yes. His daughter needs to contact the US Consulate to reschedule the interview. Be sure she has to give them the reason. The reschedule will significantly affect the waiting time as only God knows when will they have the new date available for her interview. Read these links:
https://travel.state.gov/content/travel/en/us-visas/immigrate/diversity-visa-program-entry/diversity-visa-interview/diversity-visa-applicant-interview.html