Bartestree, fifth in the Midwest Counties League, held Kidderminster to a goalless first half but conceded three times without reply after the break.
Kirsty Roberts opened the scoring and then doubled the lead, taking her goal tally for the season to 41 from 22 appearances.
In contrast, Michelle Simms netted her first of the campaign to seal a 3-0 victory.
When they return to league action next month, Harriers will be hoping to hold off title challenges from closest rivals in the championship race; Hereford Lads Club Ladies and Evesham United.
Visit clivejonespr.com for more match pics