That 79th-minute score by the Exeter Chiefs full-back in Parma in Italy on Saturday, converted by replacement fly-half Sarah Law, earned her side a second-place finish in their European qualifying tournament group behind Italy.
That means they will now go on to take part in a repechage tournament next year – along with Samoa, Colombia and an Asian side team yet to be determined – to vie for the 12th and last qualification spot for the finals in New Zealand next October.
Rollie, 26, was one of three Borderers in the team that beat Ireland, along with Hawick’s Lisa Thomson and Lana Skeldon.
A Helen Nelson penalty opened the scoring for the Scots, followed by unconverted tries from Rhona Lloyd and Skeldon, 27, either side of the interval, but Ireland hit back and were 18-13 up with just minutes to go prior to Rollie’s match-winning converted try.
Scottish head coach Bryan Easson was delighted by that 11th-hour fightback, saying: “We will think about the repechage event soon, but for now I just want to praise the grit and determination these players showed in those last few minutes.
“There was a turning point in the game when we turned over the ball in our own half when Ireland were 18-13 up and you could see our energy levels going up at that point.
“We knew we’d get another opportunity, and we took it when it came.
“The belief in this group has been building up and up over the last two years and I am very proud.”