My Son-in-law Was Recently Incarcerated Do To Domestic Abuse. My

My son-in-law was recently incarcerated do to domestic abuse. My daughter finally had him arrested; it's been coming for a long time. He has been using drugs for a long time. His arrest being put in handcuffs was witnessed by his 5 y/o and 7 y/o daughters. He will be in jail through Christmas due to a previous arrest. His 5 y/o daughter is having a very rough time dealing with him being gone. Since all these 2 kids have know for all of their lives is arguing and yelling, they (especially the younger one) don't understand why Daddy is gone but not Mom; they are angry with her and I see beg discipline problems. Any good ideas, books, articles etc. to help them understand this situation and have a better Christmas?