Please Advice! Her Husband No Longer Make Love To Her, After a Sad Incident !!!

This happened to my Big Sis. (though not blood related) she’s a Sister to me. I was one of her bridal train. After four years of marriage with a child(3 years) armed robbers came to their home. They loot away all of their valuables and raped her (three of them). Her husband was made to watch the whole show. . She was taken to the hospital and properly treated. And she was back to normal, No STDs. But ever since, (it’s been over 6 months now) her husband have refused to ‘Touch’ her. When he was confronted, he said he couldn’t bear to sleep with her after having to watch another man Making love to her. The family had set in but all to no avail. Now, she’s feeling miserable and even wish the robbers had killed her. I feel very upset and sorry for her. Mummys and Daddys in the house, any advice on how to overcome this Has anyone experience such Please help, your advice are needed.