Sofia, Bruno, and Luisa are the children of Amalia and Roberto. Enrique is Roberto's brother, making him the uncle of Sofia, Bruno, and Luisa. In relation to Enrique, they are his nieces and nephew. Diego is Enrique's son, which makes him the cousin of Sofia, Bruno, and Luisa. Since Diego's parents are Enrique and Isabela, and we know Amalia is married to Enrique's brother, Roberto, it means that Amalia is not Isabela's mother, but rather her sister-in-law. Additionally, there is no information given to suggest that Amalia has any other children besides Sofia, Bruno, and Luisa.
Amalia is Roberto's wife and they have three children: Sofia, Bruno, and Luisa. Roberto's brother, Enrique, has a wife, Isabela, and a son, Diego. Describe how Sofia, Bruno, and Luisa are related to Enrique and Diego. Also, why is Amalia not Isabela's mother?

Provide a very brief response.