[3] Upon returning to Louisiana, Roberts clerked for the chief justice of the state supreme court [3] because the career placement officer she consulted was opposed to women lawyers and there were not any law firms in New Orleans accepting female applicants.
[4] She then worked for the law firm of H. Alva Brumfield in New Orleans as a secretary and, later, as a lawyer in their Baton Rouge office[2][4] These early years of Roberts' legal career were spent representing plaintiffs in insurance and malpractice lawsuits.
She effectively used the legal system to fight for better hospital facilities, to improve patient care, and to increase the availability of mental health treatment in Louisiana.
[7] In 1969, with the support of the NOW Legal Committee, Roberts argued the first sex discrimination case appealed under Title VII of the Civil Rights Act of 1964: Weeks v. Southern Bell.
[4][3][7] The decision in this case stated that employers could not refuse to consider a woman for a job unless "all or substantially all women" could be proven incapable of performing the tasks required.
[3] The ruling was a huge victory for women and for NOW, proving NOW's investment in arguing sex discrimination lawsuits could have a positive result.
After losing her legal appeal in district court, Weeks began writing all company reports by hand in protest, rather than carry her thirty-four-pound typewriter to her desk, which resulted in her suspension.
[8] Her small stature of 5'2", was advantageous during Weeks v. Southern Bell when she used all the tools involved in a switchman's job as evidence, walking around the courtroom carrying each item and demonstrating the absurdity and discrimination of the weight limitation rules.
[7] From the mid-1960s through the 1970s, Roberts represented many women in sexual discrimination cases on behalf of LDEF often citing Title VII of the Civil Rights Act of 1964.
[5][11] When not preparing and arguing cases on behalf of LDEF, Roberts focused on the legal rights and status of women in Louisiana.
During this time, Roberts also collaborated with fellow members of the Association for Women Attorneys on Corpus Christi Parish Credit Union v. Selina K. Martin,[14] a 1978 case which led to the end Louisiana's Head and Master laws.
[5] With fellow NOW LDEF member, Marilyn Hall Patel, Roberts created the first Judicial Education Project which presented sexual discrimination research material to judges as part of their training.
[17] Roberts collaborated with several other lawyers on Corpus Christi Parish Credit Union v. Selina K. Martin,[14] a 1978 case which led to the end Louisiana's Head and Master laws.
Together Tierney and Roberts helped build a coalition to lobby the Louisiana Legislature to ratify the Equal Rights Amendment.