Jenkins made a quiet start to the series, finishing 33rd after a bike crash in the opening competition in Sydney, but claimed successive second places in the next two events.
After her London victory, a fourth place in Lausanne took her above Chile's Barbara Riveros Dias to the top of the rankings and ensured that a top-three finish in Beijing would be enough to secure the overall title.
Paula Findlay pulled out on the first lap of the bike race, while Riveros Dias faded to 44th after the run, which was dominated by Hewitt and Jenkins.
The pair broke away on the second lap and though Jenkins could not catch the New Zealander, the 27-year-old calmly finished in 1:58.40 and added the title to
her victory in 2008
, which was under her maiden name of Helen Tucker and when the champion was decided by a single race rather than a series.
'Tough' finale tested world champion Jenkins
"I'm so pleased just to win the world champs again, it's amazing!" she said.
Commenting on her second place finish in the race, she added: "It would have been awesome to take the win here, but, at the end but I just didn't have it in me.
"Because we had such a big gap I just thought 'keep it steady and hopefully I'll have something left at the end', but Andrea really just had a big kick at the end. I couldn't hang on to her."
The final race of the World Championships saw Gordon Benson finish 11th in the men's junior event. He and Marc Austin (27th) are both just 17 and have two more years as juniors.
British Triathlon's Olympic Programme Manager, Malcolm Brown summed up Britain's performance this weekend. He said: "There have been some outstanding individual performances, and even those who have been having a bad day have flogged themselves for every position. It's been an uplifting experience."
He added: "We have three world champions with Matt Sharp in the U23 and the two seniors. It's exactly the sort of position you'd want to be in going into an Olympic year."
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.