According to the U.S. Federal Bureau of Investigation (FBI), she is a high-ranking member of the Gulf Cartel, a criminal group based in Tamaulipas, Mexico.

According to multiple federal indictments, Ramos Rangel has employed family members to distribute cocaine in the United States on her behalf.

[1] According to the Federal Bureau of Investigation (FBI), Ramos Rangel has been responsible for coordinating international drug trafficking activities from Mexico to the United States since the mid-1980s.

The agents were investigating a Mexican drug trafficking ring smuggling marijuana through Mexico, South Texas, Houston, and other parts of the United States.

[10] United States officials have issued extradition requests to the Mexican government since her ascent, but acknowledge the legal difficulties of the process.

[12] With the joint participation of the U.S. Immigration and Customs Enforcement (ICE), the FBI's case has yielded arrests in Arkansas, Brownsville and Austin.

[14] In April 2011, the Cameron County Sheriff's Office in Brownsville seized 30 kg (66 lb) of cocaine heading to Chicago, Illinois.

After police seized the drugs, Cardenas advised the co-conspirator on how to deal with Ramos Rangel, recommending the use of violence, specifically kidnappings and bombs, to settle disputes with her gangsters.

[1][19] Ramos Rangel reportedly coordinated with her son, Mohammed Kazam Martinez ("Mo"), who was imprisoned at the Federal Correctional Institution in Forrest City, Arkansas, to recruit inmates to assist in distributing cocaine for her network upon their release from prison.

[20][23] In one recorded telephone conversation with Johnson, quoted in Ramos Rangel's indictment, Martinez mentions his mother's role in the conspiracy while discussing a drug debt, saying: "You owe Big Momma some money.

"), Lamont Williams ("Peter Rabbit"), Gerard Trice ("Fly"), Tarvars Honorable ("Pudgy"), and Shanieka Tatum, who distributed directly to buyers.

All of Ramos Rangel's associates deliberately concealed the nature of their activities, and used coded language and countersurveillance to avoid law enforcement detection.

[27] Authorities described the case against Ramos Rangel as atypical, as it involved an international criminal group, coordination among federal inmates, and the supply of a large quantity of cocaine to Arkansas.

The charge of using a communication device to facilitate drug trafficking activities carries a maximum four-year sentence, US$250,000 in fines, and up to a year of supervised release.