The flying winger - Player of the Match in Thursday night's Ryman Cup Final win - struck from 25 yards to level on 80 minutes before guiding home a late winner at Rugby Town FC.
Third at start of play, Coventry opened the scoring on 18 minutes through Alison Hall and were denied adding to the lead by Chloe Morgan, in fine form in the Spurs goal.
Spurs continued to probe away though and Kmita's quickfire double turned the game around in the final 10 minutes, inflicting only a third league defeat on Coventry in the process.
The victory also clinched sixth, a second-best finish in the FAWPL following last season's fifth.
The ladies' season will now conclude with two more cup finals - the Capital Cup against Charlton at Wingate & Finchley FC on Wednesday, April 27 and League Cup against Cardiff at Kidderminster Harriers FC on Sunday, May 8.
COVENTRY UNITED 1-2 SPURS LADIES
FA Women's Premier League
Report from Khalid Karimullah at Rugby Town FC
Following a dramatic Ryman Cup Final victory over Charlton Athletic, Spurs Ladies looked to cement sixth place in their final league game of the campaign at high-flying Coventry United.
Defeated just twice all season prior to Sunday, the home team started well and goalkeeper Chloe Morgan was forced into a spectacular double save early on, first to deny Marie Gauntlett’s long-range strike from just outside the area with a full-stretch save, before acrobatically keeping out Alison Hall following up.
Just two minutes later, with 18th minutes on the clock, the hosts broke the deadlock. Christina Torkildsen’s cross to the far post was guided into the far corner of the net by Hall.
Anna Wilcox and Hall struck wide before Wendy Martin was inches away from converting Josie Green's cross. Avilla Bergin then tested Charlotte McElroy from 25 yards, Hall struck the side-netting and Martin almost found Kelley Blanchflower charging in on goal.
Morgan was again needed to make two vital saves both just before, and following the break. Hall found herself free inside the area and her attempted lob was denied, prior to Hall returning the favour to Torkildsen with a dangerous cross, also denied at close-range.
Green’s delightful pass over the top almost saw Bergin break free on goal if not for Annabel Johnson’s recovery challenge.
It all changed with 10 minutes to go.
First, Rosie Kmita grabbed an equaliser with a thunderous 25-yarder that arrowed home.
Then, as Spurs maintained the pressure, Kmita fired a winner with two minutes remaining after she guided the ball into the far corner past a frustrated McElroy.
Spurs Ladies: Chloe Morgan, Shannon Moloney, Sophie McLean (Rosie Kmita 60), Alex Keown, Avilla Bergin, Bianca Baptiste, Mollie Kmita, Wendy Martin, Jenna Schillaci, Josie Green (Riana Soobadoo 73), Kelley Blanchflower.