There is a fair amount of concealing information in the Gallagher family, that’s not to say they don’t trust each other, but the full truth isn’t always necessary.  When their father is in the hospital and dying Fiona simply tells the children that he is sick but everything will be ok.  She neglects to mention the fact that he is missing a kidney and his liver is failing. Concealing information can be dangerous to a relationship. After Fiona did not tell the younger siblings that Frank was actually dying, they found out. The younger siblings were not happy because they were worried that they were not going to be able to say goodbye to their father.