At the end of the tour of England, Farrell stayed on for a period to play for Nottinghamshire. During this stint she was successful mainly as a batsman. Before making her debut for the county, she struck 123 for
Ransome & Marles against Warrington. In her debut for Nottinghamshire in the one-day competition, Farrell scored 129, contributing more than 70% of her team's 179 as wickets fell around her regularly. She took 1/20 from her 10 overs but it was not enough to prevent a six-wicket defeat at the hands of Sussex. In her third match, she took 4/20 and scored 26 in a six-wicket win over Somerset. In the next match, she was attacked by the Kent batsmen, taking 1/69 from 10 overs. She responded by scoring 122 herself, but Nottinghamshire fell 15 runs short of Kent's 6/256. In her seventh and final match for the county, she hit 80 in a 23-run win over Surrey. In total, Farrell scored 413 runs at 59.00 and took seven wickets at 25.28 at an economy rate of 3.21. The WNCL was expanded in 2009–10 with the addition of the ACT, so ten round-robin matches were scheduled, and Farrell played in all, scoring 171 runs at 17.10. Her top-score of 52 came in a 127-run defeat at the hands of New South Wales. She also had her most prolific season with the ball taking 18 wickets at 21.44 and an economy rate of 4.42. After taking four wickets in the first four matches, she took 3/32 and 2/33 against the Australian Capital Territory, but then wen wicketless in two matches against her native state, conceding almost five runs per over in heavy defeats by 127 runs and ten wickets. In the last two matches of the season, Farrell's performance peaked. She took 5/57 from her ten overs and completed three catches to help bowl out Queensland for 213, setting up a three-wicket win, and the next day, she took 4/27 and a catch to help seal a 138-run win. Western Australia won only four of their ten matches and did not make the final. Farrell had a successful time in the domestic T20s, now part of a full interstate tournament, scoring 99 runs at 19.80 and taking five wickets at 19.00 at an economy rate of 4.75. Her best score of 38 came in a win over the Australian Capital Territory and her best bowling of 3/11 came against Tasmania. Western Australia did not make the final. In the 2010 Rose Bowl series, Farrell played in each of the five ODIs during the Australian leg of the competition. She took one wicket in each of the matches and made ducks in both of her innings. She ended the ODIs with five wickets at 21.60 and an economy rate of 3.25 as Australia won all five matches. The ODIs were followed by five T20 internationals, three at
Bellerive Oval in
Hobart and the last two in New Zealand. Farrell played in all but the fourth T20 game, taking five wickets at 17.80 and an economy rate of 6.35 and she batted twice, scoring two runs at 2.00. New Zealand won all five T20s and Farrell was left out of the three ODIs on New Zealand soil. == 2010 World Twenty20 triumph ==