Way finished with 3-13 from her four overs.
Proud coach Esther Lanser said it was a far cry from the 50 extras, including 44 wides, the team had given up in their opening match three days ago.
Central Districts' goal switched to dismissing Wellington for less than the 75 runs they made against them two days before, but wicketkeeper Sam Mackinder stood firm at the top of the order, making 31 as part of a 25-run final wicket stand with Laura Martin.
Mackinder was the last to go, caught at slip off Way's bowling in the 24th over.
With only 80 runs to defend, Wellington started with a few wides themselves, with Rees (23) showing great patience to wait for the slow-medium and spin bowling to come onto the bat and then work the ball into the gaps for guaranteed singles and occasional two's.
As the skipper ran swiftly between the wickets with Pedersen, CD had swept through to 44-0 in the 11th over.
However, the procession stalled as Rees was trapped LBW by Beth Molony, while spinner Bhagya Herath came on and was very economical with 1-5 from her three overs, getting Pedersen caught when she tried to hit over the top.
Aimee Wisnewski came and went to leave CD at 52-3 approaching the drinks break, but Saffron Wilson (12no) and Way (8no) put on the final 30 runs in quick order, helped by Wellington still sending down wides and misfielding behind the stumps; CD reaching 82-3 after 20 overs.
As if on cue, the heavy rain set in only moments before Wilson struck the winning runs. The title victory was a fitting farewell for the six CD players who came runner-up in this tournament last summer, as they along with three other team-mates have aged out, meaning it will be a virtually all-new squad next summer.
For Rees, it was her second national title in three weeks after being part of the successful Central Districts Under 21 squad just before Christmas.
She said the key over the four days was the entire U15 squad had performed, sharing runs and wickets alike, which had the side effect of only three of them - herself, Gaging, and Margot Scoular - being electronically selected in the tournament's 'dream team', which was chosen from the best 12 players bowling, batting and fielding statistics, collected on the CricHq website.
"But that's ok. Everyone gets the victory in the end," said Rees.
"No one's really doing everything - we've all pitched in and had our moments."
Gaging would finish second in the overall bowling performances with 11 wickets, four behind Otago's Emma Black with 15, while Way came fourth on the list with 10 scalps.
Pedersen's five catches was second overall behind Otago's Olivia Gain with seven.
Rees finished fifth on the tournament's batting statistics and 16th in bowling, having taken Lanser's advice to be more patient and play off the back foot, given she was used to facing quicker bowling at higher age group levels
"It's hard to adjust, but you've just got to do it," she said.
She praised coach Lanser, who is a real proponent of player psychology - getting them mentally relaxed with everything from yoga to meditation.
"We got up at 6.30am on the first morning, but we stopped that. She makes us get in the circle and hold hands."
In the other Friday matchups, Auckland got home by three wickets in a low scoring thriller with Otago, reaching 87-7 chasing 86 all out, and Christchurch beat Northern Districts by 26 runs, bowling them out for 114 when chasing 140-2.
