Delphine lines up in attack, while Estelle plays in defence. The former operates on the left, while her sibling patrols the right flank. The Cascarino sisters may be poles apart on the pitch, but they could hardly be closer off it. The non-identical twins were inseparable throughout their childhood in the Lyon region and have since gone on to represent France at every youth level. Now, they are busy making waves in Papua New Guinea, where Les Bleuettes are bracing themselves for a quarter-final showdown against Germany in the FIFA U-20 Women's World Cup.

FIFA.com caught up with the duo after their side's 2-0 victory over New Zealand for a chat about what drives them forward - and what sets them apart.

Delphine, a discreet leading light
Striker Delphine has had a big hand in her country's run to the quarters. She scored against Ghana before setting up a goal against the New Zealanders and has been named the Live Your Goals Player of the Match in two of her three outings. However, despite regularly hogging the headlines, Cascarino shies away from the spotlight: "I'm not a big fan of interviews," she told FIFA.com shyly after France's first game. It is a similar story out on the pitch, where the No7 works her magic in an understated manner, using her stellar technique to leave defenders with twisted blood.

Belying her 19 years, Delphine seems to have already mastered the tricky art of doing real damage without overdoing things. She consistently makes good choices up front, even if her sister believes she could be a bit more selfish: "Delphine is too nice sometimes. She passes when she could shoot," said Estelle affectionately, before describing her twin as "fair and impartial".

Estelle, combative and mature
Where Delphine is somewhat daunted by the microphone, Estelle is anything but, holding forth assuredly and sporting a confident expression as she speaks. This assertiveness is in evidence in everything she does, as noted by her sister: "Estelle is funny, much more so than me (laughing), and she's very combative on the pitch." These qualities explain why she has been gradually shifted back into a defensive position, having originally partnered her sibling in attack.

Tellingly, she displayed the selfsame boldness last summer when making the decision to leave the nest – and Lyon, whose academy she had joined together with her sister in 2009 – in pursuit of more game time at Juvisy. "I'm the only kid in the house now, it's a bit empty without you. I get a bit bored, I've got to confess," quietly quipped Delphine, who won the FIFA U-17 Women’s World Cup Azerbaijan 2012 without her sister and so is all the more delighted that the two are back playing together at the international level.

Bright sparks
Touching as this may be, coach Gilles Eyquem has not made the twins mainstays of his team to play happy families, but rather on account of their ability. His verdict on the pair reinforces their own descriptions: "Estelle is a scrapper, she takes no prisoners and is a more assertive character. Delphine is more about finesse and technique," he said, "What they have in common is their kindness, generosity and down-to-earth nature.

"They're two players like any others - well-integrated members of the squad. They don't keep themselves to themselves and in fact they've got very different personalities," the coach went on. Indeed, as is often the case, they also have their fair share of sibling friction. As Estelle put it, "We argue constantly! The problem is that we both like being right, and since we're together all the time... But it never lasts long. We'll have it out, but ten minutes later, it's forgotten."

Sparks fly between the pair then, but neither blows up, and that helps make them two of the key cogs in the Bleuettes machine.