I know it's awful but 7 years isn't that long.
That's why abuse is so bad, it haunts you and haunts you and haunts you.
Sometimes for the rest of your life, especially if you have no support system.
Your a great Mom for supporting her and not blaming her, that will help her tremendously, perhaps more then anything else.
And I agree with the above posters, if she isn't getting a lot of benefit from counseling, maybe it's time to find a new one. I've seen about 9 or 10 couselors over the years, 2 of them were excellant and their help was absolutley priceless to me. The others ranged from somewhat helpful to very unhelpfull time and money wasters.
Did I tell you your a great Mom? I wish my Mom had been like you.