during marrige and first sathyanarayana puja she slaped manav, no mother on earth can tolerate saas slaping her beta. so now she is taking revenge on archana.
so now if archana goes out of manav's life, he will not face any humiliation from archana's family(never know what manjusha's future plan for manav's family). he wiil get all izzat what damad should get, he will become rich and more importantaly sav will b happy and i dont think , she vl creat any problem.