Mostert claimed the most valuable player award on Saturday night after working alongside Geva Mentor and Laura Langman in defence for the Lightning, who recovered from a quarter-time deficit to control the rest of the contest and run out 65-48 victors in front of 8,999 spectators at the Entertainment Centre.
Former Silver Ferns coach Taurua said Mostert's award was deserved for the "quiet achiever", who racked up three interceptions and two deflections.
"She's always a Trojan, I always see in the fourth quarter she comes out to play and gets turnovers," she said.
"This week I said to her can she do it a wee bit earlier. She's got very good movement, really light on her feet. Like a springbok."
The Giants began strongly, with Bec Bulley and Sam Poolman blocking the path to Lightning goal shooter Caitlin Bassett, and they established an early 8-3 lead before access to their shooter Kristina Brice was restricted by the hosts.
"We'd have liked to have settled a lot faster but we put a lot of pressure on to force the changes," Taurua said.
"Previously it's been very difficult to be able to contest the ball against [Brice].
"Over the last couple of weeks we've been working on that quietly. They did that beautifully and they forced turnovers."
Giants skipper Jo Harden agreed the defensive pressure of the Lightning was key.
"They had a really good defensive game against us tonight — especially in the second quarter — and when they grasped that lead it was just too hard to get it back," she said.
"They put pressure on us, me, to shoot longer than I have been and more pressure on the ball into KB (Kristina Brice).
"That really told in the end. It's about retaining composure and we didn't do that well enough."
Lightning show patience to overhaul Giants
The Lightning broke the Giants' lead down to 15-13 at the first break.
A 10-3 scoring run in the second quarter then set up a five-point half-time advantage that never looked threatened.
In the second half, the Giants found it impossible to stop the feed through to Bassett (49 goals from 51 shots), with Stephanie Wood also providing 20 assists and scoring 17 from 21.
At the other end Brice managed 24 from 29 and Harten 20 from 25.
The lead was extended to 10 goals by three-quarter time and the Lightning visibly relaxed as they romped to victory.
It is the third straight year the Entertainment Centre arena has witnessed a Queensland grand final triumph, after the Firebirds' back-to-back wins in the previous Trans-Tasman tournament.