Fire and Lies — Pamela Cowan

Two sisters solving crimes. Emma, a private investigator, recently divorced and needing to prove she competent and can go it alone. Ellen, a retired military investigator trying to find her way in the civilian world. When a case of arson turns to murder the sisters must work together to uncover the truth and confront a killer, both unaware that a hidden enemy is watching their every move. Crime solving with a hint of sibling rivalry.