Playing in the final at the Arnos Vale Stadium, T&T were bowled out for 164 off 46 overs, with Walters top-scoring with a patient 53. Reniece Boyce got 29 and Rachael Vincent, 20.
Leg-spinner Keila Elliot was the best bowler with four for 47 while seamer Deandra Dottin picked up three for 41.
In reply, Barbados battled back from a terrible start to appear on course for victory at 70 for two in the 19th over before collapsing to lose their last eight wickets for 63 runs.
West Indies Women stars Dottin and Kyshona Knight both hit 32 while Charlene Taitt chimed in with 24.
Slow medium Felicia Walters helped hurt the innings with three for 25 while slow bowler Karishma Ramharack (2-10), fast bowler Shenelle Lord (2-27) and off-spinner Anisa Mohammed (2-36) all finished with two wickets each.
Sent in, T&T got off to a decent start when Walters anchored two successive, productive stands, putting on 44 for the first wicket with Boyce and another 49 for the second wicket with Lord.
Walters struck just three fours but held the innings together, batting through until the 45th over before finally being dismissed.
T&T were well placed at 103 for two in the 24th over but lost their last eight wickets for 61 runs, with Elliot and off-spinner Hayley Matthews (2-17) also doing the damage.
Barbados were placed under pressure early in their run chase when in-form opener Matthews (9) and her West Indies teammate Kycia Knight (0) were both prised out cheaply with just nine runs on the board in the third over.
A recovery followed, however, as Dottin and Knight then combined in a 61-run, third-wicket stand to ensure the innings flourished.
Once Dottin was bowled by Ramharack in the 19th over, the innings went into freefall, with five wickets tumbling for 27 runs to leave Barbados tottering on 97 for seven.
Taitt and tail-ender Shamilia Connell (20) made an attempt at a rearguard action in a 32-run, eighth wicket partnership but Mohammed had Connell stumped in the 42nd over to signal the final rites. CMC
T&T 164 all out off 46 overs (Felicia Walters 53, Reniece Boyce 29, Rachael Vincent 20; Keila Elliot 4-47, Deandra Dottin 3-31)
BARBADOS 143 all out off 45.5 overs (Deandra Dottin 32, Kyshona Knight 32, Charlene Taitt 24, Shamilia Connell 20; Felicia Walters 3-25, Karishma Ramharack 2-10)