The Munster hooker, 18, crossed twice in quick succession during the second half in Parma as Ireland pulled away after the break.
She was joined on the scoresheet by fellow front-rowers Sophie Barrett and Hannah Wilson, as well as replacement Eadaoin Murtagh, as Niamh Briggs’ side picked up their first win of the competition at the third attempt.
“I’m buzzing,” Buttimer said. “It was such a good win.
“We have been building from the start, we were a really raw team when we arrived and it’s unreal to see how we have grown.
“This result is testament to how much work has gone in over the past couple of weeks.”
Ireland started on top in Parma and Barrett gave them a sixth-minute lead which was added to by the boot of Kate Flannery.
Lucia Scott scored in the first half’s dying moments to reduce Ireland’s lead to 13-7 but the forwards turned the screw after the interval, with Buttimer proving particularly hard to stop from close range.
“We talked about our body height with our carries when we get close to the line, about not getting too excited when we see the line,” she said.
“We came away with some good tries there. It was great for us as front-rowers - you don’t see us getting player of the match too often.
“We said at half time that we’d let them in more than they deserved. We brushed up on what we needed to, we were ruthless and kept our feet on the throat.”
Buttimer’s double was a fitting way to end a successful campaign which has seen her help UL Bohemian RFC to their first AIL title in six years, represent Munster on three occasions and feature for the Clovers in the Celtic Challenge competition.
She now has her sights set on further appearances in the hallowed green jersey having had a taste of how it feels to triumph at international level – a victory which was followed by the now traditional singing of Cranberries classic Zombie on the pitch at full-time.
“I’m hungry for it now,” she said. “We’ve all been given a chance to put our hands up during this series and hopefully we’ll keep getting opportunities to do that.
“The competition has been brilliant, really well run. We have had time to interact with the other nations, which is important, and it’s been history making.
“This is the icing on the cake of a great season.”
