Complex sentence: She won the seat of Balmain in the election on 24 March 2007 after the seat had a 3.2% swing toward the Greens, leaving a majority of just below 4%.
Split into simpler sentences: She won the seat of Balmain in the election on 24 March 2007. Though there was a swing away from the ALP, Firth won the seat with a majority of just below 4%.