Shekhar can play tricky and call Sid's dad and tell him about her preg.
They will all come rushing into the house and take her by surprise, and she won't know they're coming. They'll be like, let's celebrate! Ladoo batow, pede khao, etc
He can tell Sid in front of everyone that why don't we send you to your Maike for a few months while you're having a baby? You can meet your mom, relatives, share the good news that you're finally giving the Thakur Khandan a boy, everyone in both families will give you so much attention...
After all you deserve it...
She'll say no, she'll fight every attempt at being made to go, because then she can't make Laali's life miserable...
Then he can make her a deal, stop lying or I'll tell everyone you're lying. If you tell everyone about my Mai, no one will believe you, as no mother can kill her own child.
He knows the whole truth but he can play with Sid a bit, as she has admitted to trying to have Laali and his baby killed.
She won't go, but it'll scare her into re-evaluating her adversary, her own husband, if she keeps trying to get Laali killed with her baby.