Spoiler found in below website...Doesn't know true or not...
http://www.serialgossip.com/gossip-13471-a
So far we have seen sandhya extreme hatred for karan by runing his entire life by feeding him expired medicines and make him allergic.
Naina is aware about sandhya evilness but it's not getting family support to expose sandhya. However reason behind sandhya this evilness is still intact.
Soon in this series to come, it will revealed that kunal is sandhya son and Nirmal thought that she can never become mother by that Nirmala adopted kunal post sandhya loosing her family.
But Nirmala later gives birth to karan and sandhya cannot toletate seeing kunal getting fewer shares and less importance in family after karan entry.
Thus sandhya turns wild towards karan and destroys karan life just to put him down before NK and defame Nirmala.
What will happen about the revelation of major truth should be wait and watch.
One more spoiler also found in below website...
http://www.serialxpress.com/ek-sringaar-swabhimaan-t
We have seen both sisters not revealed their problems to their mom (sharada) but NK invites sharada and his special care towards her creates doubt on meghna and NK plan leads to the revelation of major problem around her daughter's life. We have to wait and watch will meghna stop that or not.