Help! My oldest twin is biting, pinching, hitting pulling hair

My girls just turned 19 months and we are full force into the Terrible Two's already. The oldest twin is my quiet laid back one that is now biting, hitting pinching and pulling hair when she doesn't get her way or something is taken away from her. She tends to do most of this behavior towards her twin but has started acting it out on my 4 year old and other family members. I've tried the biting back technique and that didn't work. My husband is currently deployed and we are living with my parents right now so our normal living environment has changed. Any suggestions, help would be wonderful.

Thanks!!

 

With the biting, I noticed that my kids did that the most when they were teething. It just seemed to be their default response during that time. What I did was when they bit, was say no biting and walk away from them for a minute or two (my kids did not like that). Hitting, pinching and pulling hair, were time out offenses. When they did that, I would take them out of the room, sit them on my lap, facing away from me and we would stare at the wall in the kitchen (or whatever room) for a minute (time outs are a minute per year).
I would also make sure that the other adults in the home are consistent with whatever discipline method you are using. Most of this is an age thing, my friend has a daughter this same age and she does pull hair, bite her siblings and pinch them when she is not getting her way.