Dog Depression? Hows it Cured?

I Have been Thinking about this for some time thought ide see how You guys think of it ! My Mother and father live way out in B.C and had 2 10 year old bichons , Lola and Moe. Moe had a rare type of bone cancer called Osteosarcoma. Its rather rare in small dogs but well it happened... He past away Oct. 20 and the family and mostly Lola went into a long grieving process . My parents miss him allot wont ever forget him but Lola yet hasn't recovered from the incident. She is healthy vet checked every 2 weeks but dosent want to eat like before go on walks or really move. They were well soul mates and she has to be force fed sometimes as instructed from the vet . Its Sad she was a VERY hyper girl . Is there Anyway of Fixing her depression ? Is itt Bad to get your dog a mate?