Your step daughter is jealous of the attention the others get especially the 3 year old , Now she has been found out you can go about correcting it, Ask her what her feelings are about it, dont be hostile as the worst is over and hopefully with some help the biting will stop,you could get some councelling for her, explain that its is not alright for her to bite and make sure she knows it has stopped now.and you will not tolerate it. Do this in a kind and Talkative way, perhaps as this blows over,some positive attention for her she sounds as if she is sad, could her Dad do something with Just her, make her more of the Family unit, she could be feeling very left out.How is school going if its good can you build up her self esteem and Praise her aswell.
My 10 year old son keep bitting! Not just his baby bother and sister but now kids at school! What can I do to help him stop doing this?