Ebsary made her senior debut for South Australia in the Women's National Cricket League (WNCL) during the 2000–01 season at the age of 18. Although she played in every match in her first season, she was shielded from much of the action and made only six runs. Ebsary was selected in every match in her first three seasons, but in that time, scored only 136 runs at a batting average of 8.50 and took 13 wickets from 24 matches. The following year, Ebsary raised her career average above 10 for the first time and was selected in the Australian Under-23 team. In 2004–05 she made more than 100 runs in a season for the first time, and the following year she made 149 runs at 29.80. In 2006–07, she struggled and totalled only 101 runs at 14.42 and took three wickets, and after the season she transferred to Western Australia. The change of state yielded dividends in the 2007–08 season, as she made 236 runs and took eight wickets, her highest aggregate of runs and wickets in one tournament.
At the start of the 2008–09 season, Ebsary gained selection to the Australian national team and made her One Day International (ODI) debut in the home series against India. She made 37 runs at 18.50, and after scoring 207 runs in the WNCL season, was retained in the national team. After making her ODI top-score of 86 in the Rose Bowl series against New Zealand, she was selected for the 2009 World Cup, but was in and out of the team, making 106 runs at 35.33. In June 2009, she played in all of Australia's matches at the 2009 World Twenty20 and made her Test debut against England in a bilateral series after the World Twenty20. Ebsary scored 211 runs during the 2009–10 WNCL season to retain her position in the national squad for the Rose Bowl series, but after a series of poor performances, she spent the latter half of the campaign watching from the sidelines.
Born in Snowtown, South Australia, Lauren Ebsary was one of four children—two boys and two girls—of Peter and Kaye Ebsary. While pursuing her secondary education at Snowtown Area School, attended a cricket coaching clinic organised by her school in 1996. It was there that her talent was noticed by Australian Test player and development officer for the South Australian Cricket Association (SACA) Joanne Broadbent, who said that Ebsary "had a lot of potential from the start". After Ebsary made her debut for Australia, Broadbent said "I’ve always believed Lauren had the capacity to represent her country." Ebsary was initially a tall and gangly pace bowler who mixed testing deliveries with erratic ones, including many wides.
During her teenage years before she acquired a driver's licence, Ebsary's mother drove her to the state capital, Adelaide—more than 100 km away—to play for the Flinders University Cricket Club in SACA's district women's competition on weekends. Back in Snowtown, she practised against her father and one of her brothers.