My answer would still be the same - yoy always have to do what is in the best interests of the children, and that may involve encouraging the children to accept her and like her. I know this is a toug one to deal with, but the kids have to come first ...... . This is always a complicated issue. For certain no one should falsify records, but in many places if she is living with the father she could be considered a step-parent. Better that children have an extra person in their lives to show interest in them and give them attention and kindness and caring than they have a mom and a dad who fight about what should happen.. . Whatever happens in these situations should always be in the best interests of the chldren - not in the best interests of the custodial parent or the non-custodial parent. Is it the children, or is it you, that doesn't want her at the school events? I get a little sense of some anger and bitterness here, and that is not unusual, but don't let it cloud issues. If this woman is important in their dad's life it is best that you try to have at least a civil relationship with her. Why do you say the children did not want her at the school events? Did you tell them they shouldn't want her? What harm does it do for the children to have an extra person clapping for them and cheering them on at school events? Children need all the love and support they can get.. . Try to set aside your own feelings about this, and approach it from the perspective of doing what is right for the children. I am not trying to decide for you what is right, but in many cases it is best to come to peaceful terms with the new woman, and accept that she will be in your children's lives. Encourage the children to accept her and get along with her - she may be with their dad for a while, and kids need their dad too.. . . You may have a chance here to be the one who steps up and refuses to put the children in the middle, and does only what is in their best interest.