I saw this video a couple of days ago on a different channel and it was suggested that this little kitten has two independently functioning brains since at some point during development the twins didn’t separate successfully hence her head swaying from side to side as she tries to maintain her balance.
Usually the survival rate of such births are very poor but some kittens born this way have survived well into adulthood with the receipt of good care from their human parents.
She seems to be a precious little darling and is deserving of all the love and care that she is being given. All the best to her.