Illegal relationship

My wife (31) had an illegal relationship with her college student (23Y) who was depressed due to love failure. Both started as friends but ended up kissing and sexting and calling over the phone, talking for several hours. I caught this and separated both. Now both have not been in contact for more than 3 months. The student is suspended from college, but my wife is still working in the same college (private). She said it was her feeling. As I truly loved her she said I should not ask any question about this relationship, rather she said I have to encourage her. Now she said she will live with me without any physical relationship. We have one daughter studying 4th standard. My wife depends on my money only. This is not the first time, it is happening every 5 years (from 2013). Last time it was a school student (18 Years). It was also broken. This time myself and my daughter both got disappointed. Now she said she never loved me for the past 10 years. But my marriage is a love marriage. She loves me more until this new relationship. She also said she would leave me after 8 years (to support her daughter upto +2 school education) and want to stand on her financial support. Now she is getting only 10 thousand Rupees. What is the advice for me and my daughter? Kindly help. My daughter wants to live with her mother.