what purpose will tanu's plans to kill pragya achieve...

so if tanu's plans are now to kill pragya again...exactly what will she achieve...dadi..purab..rachna...akaash...sarla ma knows the baby is not abhi's...so will she have to get rid of all of them as well...what will this really achieve...abhi already told her he doesn't love her...he has a responsibility towards the 'baby'...the chances of her trying to get pragya to give abhi a divorce is very very slim at the moment...I really don't know to what extent the cv's wish to have tanu as a serious threat to abhi and pragya...but she really isn't...at all...