There can be debate about some of the changes England have made since their Ashes drubbing - the batting order continues to divide opinion - but there can be little argument about one of the major successes over the last couple of months with the introduction of legspinner Sarah Glenn.

Since making her debut against Pakistan in Kuala Lumpur last December she has 13 wickets at 13.69. Throw in eight in three ODIs and it's a mighty impressive start to an international career. It's looking like a good thing Glenn made an early switch from bowling seam.

"I watched some video clips, of Shane Warne maybe, and decided on legspin because it seemed more fun," she said in an interview with Wisden before this tour. "It wasn't until I got a bit older that I realised I could add something a bit different to the teams I played for."

Her call-up came after an impressive Kia Super League campaign (the tournament that has now been disbanded for the introduction of the Hundred) in which she claimed 11 wickets at 18.72. In that was a return of 3 for 25 against Lancashire Thunder which included bowling Harmanpreet Kaur first ball.

She has impressed since arriving in Australia. In the second game of the tri-series ahead of the World Cup she claimed 3 for 28 against Australia which including trapped Ellyse Perry with one that went straight on and getting Rachael Haynes caught-and-bowled with a wrong 'un. In the next outing against Australia were the scalps of Beth Mooney and Meg Lanning. Big names throughout.

In the first match of the World Cup she gave England a chance when she drew a return catch from Marizanne Kapp before South Africa clinched the game in the final over. Thailand was a routine affair, skipping through four overs wicketless for just 11 runs under no pressure, but against Pakistan she clinched what are early career-best figures.

"It's always something I've dreamed of doing, but I never thought I'd kind of get this far so it's really exciting for me," Glenn said. "But I think a lot of the girls helped me get there, just their support of me and helping me fit in, so I think that was a big factor for how I've got here."

She is forming a very telling partnership with left-arm spinner Sophie Ecclestone, the No. 3-ranked T20I bowler who has established herself as a vital component in the England attack, which brought 5 for 27 in their combined eight overs against Pakistan, and Glenn believes having Ecclestone at the other end has been another key part of her early success.

"We're a similar age but she's got a few more experiences in terms of the England side. If at any time I was kind of nervous or unsure about something she's always there to talk it through with, on and off the field, so she's a real key asset to the team."

Two of Glenn's dismissal against Pakistan were bowled meaning that, albeit from a small sample size, more than a third of her T20I wickets (five out of 13) are either that form or lbw, a testament to bowling at the stumps which she sees as her strength. Her first wicket in this match stood out as it came the ball after Javeria Khan had driven her second delivery of the night over cover, a challenge Glenn has focused on responding to.

"I've just learnt to try not to beat myself up about it, especially in T20 because someone is going to play some really good shots, and even if you bowl a good ball, it can still go for a boundary," she said. "I'm trying to focus on the next ball and kind of park it.

"I've always bowled stump to stump because I don't naturally get quite as much turn then. I'm following on from [KSL] back at home. I had a basic plan of how I was going about bowling, and when I discussed that with [the coaches] at Loughborough before heading out to Malaysia, then out here, they agreed to just keep it the same and keep it basic. I'm still working on variations as I go along to naturally bring into my game."

England's tournament now moves to the Sydney Showground stadium for their vital final group match against West Indies at a venue known for taking turn, as Poonam Yadav showed against Australia, with the semi-finals, should things go to plan for England, at the SCG where spin has been in vogue this summer. Glenn could yet have a major say on how this tournament pans out. Finding a legspinner has been a major aim for the England team and, on early impressions, it appears as though they have made a wise choice.

Andrew McGlashan is a deputy editor at ESPNcricinfo