Desiree Ellis's charges entered this weekend's clash with the advantage after they recorded a 1-0 win in the first leg in Lesotho on Wednesday evening.
Two minutes into Sunday's game, Banyana broke the deadlock with Jermaine Seoposenwe firing home after being set up by Nothando Vilakazi.
Chantelle Essau doubled the lead in the fifth minute with a finish from close range after the goalkeeper failed to hold onto Kgaelebane Mohlakoana's initial strike.
Banyana thought they had a third goal in the 21st minute when Essau slotted home, however her strike was ruled out for offside.
Lesotho, meanwhile, did manage to carve out a couple of openings but were unable to test Banyana goalkeeper Roxanne Barker.
Six minutes into the second half, the home side extended their lead with Essau registering her second goal of the encounter.
Banyana didn't have to wait long for the fourth as Khanya Xesi delightfully picked out Seoposenswe, who made no mistake from close range in the 59th minute.
There was time for more goals and, in the 77th minute, a debut goal from Hildah Magai added to the scoreline.
The sixth goal arrived in the 82nd minute as Seoposenswe turned provider to pick out Leandra Smeda, who nodded home her second goal of the tie.
That proved to be the final goal of the half as Banyana win the tie 7-0 on aggregate and qualify for the tournament in Ghana.