Mother cat and two female kittens. All well, close bond, kittens still sleeping close to mother, sometime comfort suckling.
Kittens were spayed yesterday (5 months). Mother now has taken against them, growling and hissing if they come near, swiping at them if they come too near.
Maybe the "vet smell" will wear off and she'll recognise them again, but at the moment it doesn't look like happening.
Meanwhile mother is stressed at the invasion of alien kittens, kittens are stressed because mother is rejecting them...