Spurs did everything but score in normal and extra time as the final went down to a penalty shoot-out. Charlton missed their first two penalties and couldn't recover as Wendy Martin, Sophie McLean and Bianca Baptiste all slotted home to allow Katie O'Leary to fire home the decisive spot-kick.
It was no less than Spurs deserved after creating a host of chances and hitting the woodwork three times.
The captain's night almost mirrored the team's - Jenna had a header somehow saved by Megan Lynch in the second half then had her penalty saved in the shoot-out before finally getting her hands on the trophy after Katie's winner.
"It's an amazing feeling to win, I can't put it into words," said Jenna, one of three players alongside Wendy and Bianca to rack up over 100 appearances for the team.
"We had such a good build-up to the final, the Club did everything to prepare us and it was up to us to go out there and do it.
"I thought we were the better team, we had so many chances but we just tend to do things the hard way!
"I felt awful after missing the penalty but I knew if anyone was going to score a decisive penalty it would be Katie. I'm thrilled for her because she's been out injured since November and this was her first game back.
"I'm so proud of the team and the squad. I'm so happy I could cry."
Below: Karen and Jenna with the trophy
"I've been out four months and one day," reflected Katie. "I actually felt quite calm going up to take the penalty. I knew where I wanted to place it, I put the ball down and paused, it just felt like all that hard work in coming back was for that moment and to do it for all the players and all the coaching staff was an amazing feeling.
"We've worked so hard for this trophy and I'm just so proud that I managed to stick that penalty away for everyone. It made all that work worth it, 100 per cent."
Spurs enjoyed the best-ever season last term but one thing was missing - silverware.
Manager Karen Hills stated from pre-season that the team was determined to lift a trophy, not least after losing the same final to the same opponents last term.
"I'm so proud of every single player," said Karen. "We thoroughly deserved the win. We kept our nerve in the penalties and fair play to Katie, it was her first game back and she put in a real shift. To score that winning penalty was brilliant for her.
"This season has been all about winning a trophy. The team has gone from strength to strength, we're continuing to build and you can see that from some of the results to get to the three finals. Now the first one is in the bag hopefully we'll carry this momentum to the end."
Below: The players' reaction as Katie slotted home the winning penalty
The teams will now meet again in the Capital Cup Final at Wingate & Finchley FC on Thursday, April 27.
The third of the three finals is the big one, the FA Women's Premier League Cup Final against Cardiff City at Kidderminster on Sunday, May 8.
However, before all that, Spurs have more business in the FAWPL with their final league match of the campaign at Coventry United on Sunday - they need a point to absolutely guarantee sixth place.