Carmen Planas was the daughter of Concepcion Lim and Illuminado Planas. Her siblings include Attorney Charito Lim Planas (Former Vice-Mayor of Quezon City), SocialiteAdela Planas-Paterno (former Miss Visayas) & businessman Severino L. Planas. She was a consistent class valedictorian from grade school through college. At the Zaragosa Elementary School she was top pupil in her fourth grade. In the seventh grade she transferred to Collegia de Sta. Rosa where she was also a top student. She attended high school at the Holy Ghost College (now known as the Holy Spirit College).She enrolled in the prelaw course at the University of the Philippines, where she became a scholar. Her oratical and debating ability and zeal earned her gold medals in the U.P. College of Law. Once her debating ability was tested on the issue of women suffrage. She was assigned to take the affirmative side, and advocated it brilliantly. Then she was assigned to argue the negative side on the same issue, she defended it with even more convincing eloquence. This display of rare talent earned her two medals. She also won the Spanish declamation contest.