"There's been no change since yesterday, so we're taking it as a plateau before he has another leap in the right direction," Mr Preston said yesterday.
"He's in an intensive care unit where they are keeping him away from distracting noise."
Ms Ferne, 68, suffered fatal head injuries in the fall down the stairwell of her son's home. Mr Preston said there would be a memorial service for his mother at a local mortuary before her body was flown back to New Zealand this morning.
"We've spent some money and told them to make it colourful. We've told people to bring drinks and people will sit around the coffin and just talk and toast to her," Mr Preston said.
His brother Sean said the money raised so far through the trust would contribute to new equipment at Ho Chi Minh Children's Hospital, which is desperately short of some basic equipment.
"From all the tragedy and the sorrow of the last few days when I clicked open the bank account to see how it was tracking it really choked me up seeing the support from all over New Zealand," Sean Preston said.
"We just really want to thank everyone for their generosity, it means so much to us and it has really helped us in terms of getting through this."
He said he had made a personal commitment to ensuring the money was spent appropriately.
"We're going to see exactly what the hospital needs and then physically deliver it because a lot of money gets lost in black holes here."
People wishing to donate to the Julie Ferne Memorial Trust can deposit funds in ASB account 12-3198-0065427-00.
