Several roads and recreation sites remain closed, with dairy farmers forced to dump thousands of litres of milk.
Nicole Ferraro said her father and brothers stayed to defend their properties and managed to save most of the herd, their homes and dairy but the rest of the farm suffered "a blackened fate".
"For the short term, their main focus is the well-being of the animals, keeping the cows milked and fed, as well as the supply of diesel which is needed to run the generator to keep the dairy operational and the milking herd healthy," she wrote on Facebook.
Western Power says thousands of properties remain without power but burned trees and debris in danger of collapsing must be cleared before crews can rebuild the network.
About 835 people have registered at two evacuation centres.
People wanting to help can donate money through the Lord Mayor's Distress Relief Fund. The state government has already committed A$1 million ($1.06 million).
Doreen Jones, from Emergency Wildlife Care Bunbury, said the centre was beginning to receive animals that had been recovered from the fire zone, suffering burns and smoke inhalation.
"We've had two ring-tailed possums, a brush-tailed possum and a joey ... handed in to various people and vets."
Jones was concerned the fires may have decimated the echidna population in bushland near Yarloop.
