Born in Tunis, she won her first international medal at the age of fifteen, taking the pole vault title at the 1999 African Junior Athletics Championships. She became the first women's pole vault champion at the 1999 Pan Arab Games, following its introduction into the programme. Balti cleared four metres for the first time in 2000 and went on to claim the gold medal at the 2000 African Championships in Athletics. From 2001 onwards she based her training in Toulouse in France. That year she achieved an African junior indoor record of 4.10 metres.