They defeated Louth last weekend to get there.
A brace from Ciara Blundell and a Leona Archibald penalty proved enough to see Westmeath into the All-Ireland Intermediate semi-finals.
They emerged top of their group following a 3-11 to 1-5 victory over Louth yesterday.
It followed a nine goal performance against Longford in their opening game and sets up a clash with Roscommon in two weeks time.
Roscommon themselves had convincing wins over Wexford and Offaly to reach the knockout stages and will provide the Lake County with their stiffest test to date.
A 5-10 to 4-4 win over Offaly yesterday condemning the Faithful ladies to a winless championship year following defeat to Wexford two weeks ago.
Laois were unlucky not to join their neighbours in the semi-finals.
They defeated Kildare at the weekend to win their third group game, but lost out on score difference to table toppers Clare, who defeated the O'Moore County last weekend.
Ultimately it was the banner's demolition of Sligo (7-18 to 0-2) yesterday which got them over the line.
Laois could only manage a 5-8 to 1-5 win over the weakest team in group 4 but it has been a very positive showing for Donie Brennan's team who will look to build on this and make the knockouts next season.