Girlfriend already married, husband threatening to kill

Dear Sir, my lover wants to elope with me and she is married,having 5 years daughter. I thought to take divorce and later marry her legally but her husband not at all agreeing for divorce and still he dont know she is Loving me from her childhood and planing to elope with me. She asked her husband she is not interested to stay with him and wants to stay separate along with her daughter and asking for divorce. But he warned her if he came to know she is loving someone else and if she talk once again about the Divorce, he will kill her and he also will commit suicide. We dont know how to elope as it leads to major problem if he complaints to police.Even she told we right a letter to concern police station by willfully i am eloping with my Lover and please dont consider any complaint against us. If her husband wants he can marry anyone as i wont come in his life here after.