Alienation of Affection and Child Visitation

My husband admitted to long-term affair (about 3-4 years) and a child (4 mos now) born from that affair this year. We are currently trying to work out our marriage. His ex is constantly calling him daily and using his child against him. Her calls are also putting a strain on our marriage because he feels he has to answer every time she calls in case it is urgent about the child. After hearing about the affair and the child it has been very hard to deal with every day. Even though he has told her he’s working on his marriage with me she keeps calling. Can I sue her for alienation of affection even if we are still together? We had been on the brink of a divorce but finally decided upon counseling and working on our issues. However, every day is still a battle with her calling multiple times during the day.
In addition, she won’t allow him to see his child if I am present and of course I have issues with him being at their place. As the father can she deny him the rights of visitation because he wants to share this child with our family (we have 2 small children of our own)?