In 1990, still only eighteen, Haggett was the UK's number one female high jumper, winning the AAA Championships with a personal best of 1.88 m, defeating Olympic finalist Janet Boyle. A week later at the World Junior Championships in Plovdiv, Bulgaria, she again cleared 1.88 m to win the bronze medal. She would remain the only British woman to win a medal at the World Junior Championships in the high jump until Morgan Lake won gold in 2014. She ended the season by competing at the European Championships in Split. As the only British entrant, she managed 1.80 m and was eliminated in the qualifying round.