A Female has attacked the baby from another female budgie when she was gone to feed herself . I suddenly came to the room to see what happened and noticed this . budgie's mum came to the nest but I feel like she is now killing her own budgie instead of taking care of the attacked baby . She is constantly pointing her beak to the  baby's wounds . I couldn't see that so I have separated them . Please could you let me know if that is common or the mother doesn't want this baby now as the baby was attacked by some other female 

Seperate them ASAP and let the male take care of the young ones.