It's a sad time in the Brown household. In ET's exclusive sneak peek at Sunday's episode of 'Sister Wives,' Janelle reveals her mother, Sheryl Brown, died after battling cancer. With Christmas two weeks away, Kody knows there will be a risk of COVID-19 exposure at Janelles mom's funeral, but he shares why attending is more important than getting the family together for the holiday celebration. 'Sister Wives' airs Sundays on TLC.Exclusives from EntertainmentTonight :