Rojas had her first competitive jumping success at the 2011 South American Junior Championships, where she won the high jump. Due to this win, she received her first spike shoes, given to her by Marco Oviedo of the Venezuelan Athletics Federation (FVA) after Velásquez challenged the FVA to support her if she won. She was then defeated at the 2012 championships, managing only fourth, but performed better in higher-level competitions that year, jumping to take sixth at the Ibero-American Championships and claiming the bronze medal at the South American Under-23 Championships.