That’s likely the child’s mother. The child is likely already infected but not symptomatic just yet.
Most of the family members who might have cared for the child under normal circumstances are likely dead or infected themselves.
If you came down with Ebola, knowing you’d cared for your children (changed diapers, prepared food for) and had no one else to care for them would you leave them at home by themselves?
Since in that part of the world they don’t trust the government or modern medicine I doubt that they know anything other than people are dying.....in certain areas it is being called a punishment by God