Vladimir
You had 1 son and 1 daughter. He cheated on you. You divorced him. He manipulated his children and now they stay with him. He married the person he cheated on you with. Your children call that woman mother. That woman (Vasilisa) cheated on Vladimir. The person with whom Vasilisa cheated on Vladimir shot your daughter on purpose.
About Vladimir
You had 1 son and 1 daughter. He cheated on you. You divorced him. He manipulated his children and now they stay with him. He married the person he cheated on you with. Your children call that woman mother. That woman (Vasilisa) cheated on Vladimir. The person with whom Vasilisa cheated on Vladimir shot your daughter on purpose.