Why can the discussion of Minerva's interests endanger the family according to the narrator's comment in In the Time of the Butterflies?

Minerva is the narrator of the novel. She knows that the dictator Rafael Trujillo demands absolute loyalty and subservience from every Dominican. In his thirty years in power he had built up a totalitarian state and a cult of personality that utterly controlled the nation.
Trujillo may have ordered killed as many as 30,000 people during his time in power. Other political parties were banned, and the press was censored. The capital, the capital province, the nation's highest mountain, and many public buildings were all renamed after Trujillo. The nation's money, churches, and even license plates all praised Trujillo. The nation was heavily militarized and had forts everywhere, even though it had only a single weak and poor neighbor, Haiti.
Trujillo also personally targeted anyone he saw as an opponent. This included Minerva's family. He allowed Minerva to attend law school, then withheld her degree. Finally he orders the three sisters murdered.