Marjan,
This is a tough situation for you, and I'm so sorry you are going through it.

It's hard not to feel guilty whenever we talk about family members; especially so if it's a parent.
Many of us tend to feel that we shouldn't talk about hurtful things that our parent did to us in the past...and what they still do to us.

Is her visit going to be a short one? If so perhaps you can just do the best you can until she leaves?
If she is going to be there for while then you may want to think about setting boundaries with her. You have every right to do this; because she is your mother it does not make it all right for her to be abusive toward you and your siblings.
It's going to be tough with her being so abusive, but you have to protect yourself.

If she gets angry when you/your sisters tell her No
or when you ask her to stop doing something...it's her problem. Allowing her to continue abusing you only makes it easier for her...
If all of you are consistent in what you are saying and doing about your mother, it can be of tremendous help.

Just my opinion but she cannot make you get married or make your sister divorce her husband...
Don't give her that kind of power to control your lives.

I understand how difficult it is to stand up for yourself when you are used to taking her abuse all through your childhood.
If you want to be happy and have peace in your life, please consider counseling to help you work through your feelings.

You are a worthwhile human being and deserve to be shown respect...
Best wishes to you in finding your way through this rough time.

In Peace,
Catherine