Intro kids to new GF/BF during divorce

A friend of mine recently found out her husband has been having an affair for the last 8 months. He moved out and is now living with the “other” woman. They have been married for eight years and have a 7 and a 4 year old.

She JUST filed for divorce.

Her husband has already introduced the children to his new love against his wife’s wishes.( He didn’t inform her of where he was taking them) She stated to him that she understood this woman was going to apart of his life but would he please refrain from introducing her for 10 weeks so the children can first get used to him not living there, then to the fact of the divorce, the new love and him living with this new person and her children.

My questions are:
How does this look from a legal stand point?
What is HIS lawyer going to say about this?
What is the time line recommmended by psychologists in this area?
IS there anything she can;agally do to keep him from taking them around this woman?

Please help. Thanks.