Newly Widowed Disabled Sr, Mom

My brother, Richard, suddenly died on July 13, 2018. He was the breadwinner. His wife Corrine is now a widow. She is 64 and on Social Security Disability due to her physical conditions. She and my brother, as total legal guardians, were raising their 2 grandchildren, Landon (8) and Aiden (10), victims of severe  physical abuse., with PTSD, and other psychological problems. Corinne's disability payments, combined with my brother's death benefits, only amount to $1,300 per month. Her mortgage alone is $1,500 per month. As she cannot work, and has two children with severe needs to finish raising, I am asking for community support to pay off her mortgage, and help with her monthly needs. The need is great, and urgent. Any assistance will be greatly appreciated.