Bullied rabbit?

Question
I have two female three month old dwarf lops who are sisters, I've had them for about two months and up until recently they got on fine.
Yesterday evening, I checked on my rabbits and stroked them for a bit, and noticed one of the rabbits was clambering all over the other, at first I thought this was fine, but became concerned when she started to pull out hair that was not loose on my other bunny. I separated them by picking the 'bullied' one up, but as soon as I put her back into the hutch the 'bully' chased her and jumped on her and continued pulling out her hair. The bully also tried mounting my other bunny...but they're both female??
They are totally opposite in characteristics, in that one is really outgoing and the other is very shy towards me.
I have separated them temporarily (the 'bullied' rabbit is currently living in a run indoors- ideally I'd like them to get on again).
I have also noticed that they seemed to have swapped personalities since being separated; The 'bully' is now very timid and shy towards any contact, and the other rabbit is now outgoing. Any advice would be greatly appreciated.  

Answer
Hi Zena,
 The first thing I suggest is to make sure that they are both female..this behavior sounds like the description of 2 males. Once males have hit maturity(which is around 3-4 months) they exhibit awfully aggressive behavior towards eachother.  Separating them is the only thing you can do,other than neutering them,which still may or may not work for the fighting.
 Two sister females would unlikely become aggressive with eachother especially when they have been together since birth. My females all live peacefully together,with the occasional squabble...but nothing like 2 males behave.
I recommend having them sexed by a qualified person who knows what exactly to look for..as this is a tricky procedure for even the best experts to do. Most pet stores will sell you 2 bunnies and not really know what the sex is,,,especially when they're under 3 months old.
 If they are both male,then the only thing to do is to have them neutered,and start from there.  If they are both female,spaying them would also help.
I wish you luck,Elizabeth