Help Pleaseee!

So I Have a momma cat about 9 - 10 months old, originally had 5 but we gave away 2 well recently shes been attacking just this one kitty, shes female and about 2 months old but doesnt attack the other two kittys. She lets all the kittys drink milk still and they are trained to poop in the box

Have they all been spayed? There may be some hormonal issues going on with mom.

Is the one she "attacks" a feisty, busy little kitten? Are the other two kittens more laid back? Mom is probably teaching this kitten manners! It looks like an attack but she is actually disciplining her kitten. This is how kittens learn how hard to play, and not to bite and scratch. Eventually she will do it to the other two as well. It's how they learn, and it starts around this age! It's why it's recommended that kittens stay with their moms for 12 weeks before being re-homed. [emoji]128522[/emoji]