Can a person date when divorce is going on. Been separated for more than 1 and half year.

Hi, My sister was married, but their marriage dint work out because her husband used to phsyically hit her, and not let her go to work. So they decided to go for a divorce in 6 months from the date of marriage. And they have been separated since a year and a half. Their first hearing was done in october 2019. Due to lockdown their last hearing got delayed alot and its still pending. - they went for a mutual divorce. -Her husbands family was supposed to return her belonging, they have signed papers from us. Saying we have received her belongings, but they said they will return it in a month, now its been more than a year, this was all in front of the lawyer. Even the lawyer is aware that they havent given our stuff back yet. And recently she has started dating. A month back. So now when we asked her husband to send us her stuff since its been more than a year. He calls her and says he will throw all her stuff out, Threatens our dad. And speaks with abusing language on calls. And says that she slept with some guy will file a case against her. He keeps forcing her to accept that she is having an affair to file a case against her. For a woman her character is everything. He Keeps calling her with dirty names destroying her character. 1> is it a crime that she is dating during her divorce. Its been more than a year they have been separated and she started dating just a month back. and just last hearing is pending. Which was supposed to be done long back, But got delayed due to lockdown. 2> What actions should be taken? 3> how can we get our stuff back.?