Mazloum suffered from paralysis of the legs (poliomyelitis) at the age of two, and walked again after years of care by a paediatrician and his wife who was a ballet dance teacher.

In fact she was a child star from 1939–1945, she performed daily watched by her mother, who was her manager, working in Alexandria in the summer and in Cairo during the winter.

The 10-year-old Mazloum appeared in her first film, I prosfygopoula ("The refugee girl", 1939), which was made in the Greek language and starred Sophia Vembo with a screenplay by D. Bogris.

As a child she danced at the famous Casino Opera, run by Badia Masabni, where great Raqa Sharki dancers started their careers; there were two shows every day, a matinee for the whole family and an evening performance during which alcohol could be reserved.

In the 1940s and 1950s the strikingly beautiful and talented young performer danced and acted in the best Egyptian theatres, creating her own choreographies; she also performed/acted in about 17 films.

Her daughter Marianna said during a lecture on Mazloum's life and career in CID, UNESCO (International Dance Council) "My mother's performance was in demand, as she had the privilege of being the only modern dancer in Egypt at that time."

Marianna also mentioned during her lecture, "My mother met and talked with remarkable human beings: teachers, musicians, writers, poets and archaeologists, who knew a lot about the culture and tradition of Egypt she was also an avid reader and researcher who studied books in the National Egyptian Museum, looking for descriptions of dances and costumes from ancient times; the director gave her special permission, provided she handled the fragile manuscripts with white gloves on.

When attending private family parties of the elite, she would observe their dancing, which had a more refined style than the balady (Native) or the shaabi (Popular) – she called that refined style: 'hawanem'" Eventually, Mazloum divorced her husband, she reopened in 1951 her ballet school and in 1955 returned to performing and formed her own dance company; she established her folkloric dance school in Cairo for the training of the members of her company; she was the most famous folkloric dancer in Egypt who inspired a whole generation of dancers and choreographers at that time.

She was the pioneer who attempted for the first time to apply Egypt's traditional legacy of Folkloric Dances into a dramatized artistic form.

Mazloum was appointed by the Ministry of Culture to be his assistant for the protection of the Egyptian content of Classical dance.

In 1961 another ambitious project was formed: the establishment of a National Folkloric Academy under the direction of another Russian, Boris Ramazin who was the first assistant and dancer of the "Moiseyev Dance Company" in Russia.

The Minister of Culture, Dr. Sarwat Okasha, was so enthusiastic about her work that he used to buy tickets for the Egyptian people, so that everyone could see her shows.

Her structured pedagogical method of teaching and her excellent teaching skills, her patience and her humorous personality, as well as the passion for life made her seminars a great adventure in knowledge to her students; it brought in no time a drastic progress and an improvement in the dance quality of the participants in each seminar.

Mazloum wrote in one of her articles "Archaic dance still influence our moving center, for they are rooted in the cosmic memory of our planet.

Her daughter Marianna Roussou Mazloum (also known by her stage name Marhaba) was her foremost student who received continuous first hand instruction from her mother since childhood and always assisted her during the workshops, as well as taught for more than 40 years, offers seminars and lectures – backed by accurate documents and rare photos - on Nelly Mazloum's life, dance method, legacy and work.