I am happy that your girls are in counselling; the more they work through now, the better off they will be down the road.
Be as supportive as you can, and encourage them to talk if they need to, and vent their anger without you being defensive. When your oldest girl said that he had abused her prior to marriage, you noted that had she told you, you would never have married him. To a child that is like saying there is fault with her silence, and she may feel somewhat that she is responsible for not only you marrying him, but for contributing to her own abuse, which is very far from the real truth.
When you talk to them, let them know simply that you love them, and you will do everything in your power to help them. Try not to minimize what may seem to you to be exaggerated outbursts, hateful or hurtful words of judgment to you personally, or misinterpretations of events, and who is to blame.
Right now they need honesty and consistent responses to test your loyalty only to them, and they need to, in their own way, learn how to trust you again.
The counselling will see all of you through this terrible time, but you should expect a lot of anger, which is a legitimate expression of how your girls feel, at least in the short term. To not allow them to express how they feel in an age appropriate way, is to deny their feelings and emotions, and these things need to get out.
Reasure them that you will never make the same mistake again, there will be no men in your life until your girls are taken care of no matter how long it takes, and you will protect them at any and all cost.
Keep doing what you are doing, stay the course, weather the storms, and be prepared for what is to come.
Please seek help in how to cope with this, and appropriately help your daughters. You too, need to seek assistance to work through this. All of you together, working hard and being understanding, tolerant, and non judgmental, will go a long, long way in everyone's healing.
How you take care of yourself, will directly affect how your children recover.
Eli Newberger, M.D.