The New Zealand allrounder helped guide the chase alongside Ellyse Perry to ensure they were ahead of the DLS
The tournament will feature teams from five different countries with a prize money of US$1 million
Van der Merwe was previously with the franchise in the first season of the SA20, helping the team to the title
Marizanne Kapp rocked the top order with three wickets Tahlia Wilson and Anika Learoyd steadied the chase
Invincibles still in the hunt for top spot as Winfield-Hill and Kapp ease hosts to London Derby win
Hosts wrap up their seventh victory of the season with a day to spare
Gloucestershire fight back through Singh Dale before tumble of wickets
WA were 133 for 3 chasing 167 but lost 7 for 31 with McAndrew taking a career-best 5 for 40. Earlier, Bryce Jackson took the best-ever 50-over figures for WA of 6 for 31
The experienced Jess Jonassen has been omitted after losing her spot earlier this year
The New Zealand allrounder helped guide the chase alongside Ellyse Perry to ensure they were ahead of the DLS