SLIDESHOW: Jessica Ennis-Hill turns 30 - Exciting new decade dawns for Sheffield's golden girl

Today marks her 30th birthday. The next decade has a lot to live up to.

And yet this summer could turn out to be the pinnacle of the Sheffield heptathlete’s career. The poster girl of London 2012, who won Olympic gold in such emphatic fashion three and a half years ago, now has an even greater challenge ahead of her: to retain that title in 2016, having had a baby in the intervening years.

Ennis-Hill - with three world titles, one indoor and two out, and a European crown to go with her Olympic success - is already arguably Britain’s greatest ever female athlete. Another gold in Rio will end the argument. Only twice before has an athlete won Olympic gold. Jess’s task is to do it in the most gruelling event of all.

She has, however, reconquered the world once already, winning gold at August’s World Championships in Beijing, 13 months after the birth of son Reggie.

Rio will prove a tougher competition than Beijing. Her two great rivals, fellow Briton Katarina Johnson-Thompson and Canada’s Brianne Theisen-Eaton, won’t under-perform so dramatically again.

“The standard will go up again,” said Ennis-Hill, who was surprised her score of 6,669 points was enough to win in Beijing.

Balancing training for seven events with the demands of being a mother is a juggling act, but Ennis-Hill said after her win in Beijing: “When you become a mother for the first time it changes your whole life. I am a happier person so I think that can transfer positively into my performances.”

Anyone who thought motherhood would dim Ennis-Hill’s competitive instincts was wrong. “I always knew that I wanted to come back and perform at this level” she said. “There were people that probably thought, ‘She’s won the Olympics, she’s ready to retire’. That gave me motivation to show I can come back.”

Coached by Toni Minichiello since the age of 13, as an up-and-coming athlete Ennis-Hill was nicknamed ‘Tadpole’ by compatriot Kelly Sotherton. It was a barely veiled dig at the young pretender’s petite stature. And it was tag to which she would prove laughably unsuited.

At 5ft 5in she has been towered over by her rivals for her entire career. But for an athlete wrought from pure Sheffield steel, it has mattered not one bit.

Ennis-Hill’s first senior international medal came at the 2006 Commonwealth Games in Melbourne, where she won bronze, Sotherton winning gold.

She finished behind Sotherton again the following year at the World Championships in Osaka. She suffered a major setback in 2008 - Olympic year - though.

Three stress fractures in her right ankle not only ruled her out of the Beijing Games, but threatened her whole career.

Her response epitomised the relentless drive she has become known for throughout her career. The next year she was world champion.

She won the world title indoors and European title outdoors in 2010 before having to settle for silver behind Russia’s Tatyana Chernova at the 2011 World Championships in Daegu. That is far from the full story, though. Ennis-Hill is still waiting to see if she will be upgraded to gold after her rival was exposed as a drug cheat.

She missed the 2013 worlds with an Achilles injury, marrying husband Andy in May of that year, while 2014 was given over to maternity leave.

Indeed, Ennis-Hill has still only completed two heptathlons since London 2012.

The multi-eventer will start 2016 by racing over 60 metres hurdles at the Glasgow Indoor Grand Prix on February 20, with all sights set on Rio.

Another triumph there would appear the perfect way to bow out, although the draw of a last hurrah in London at the 2017 World Championships would no doubt be strong...