I just remembered something from an old episode. Remember on Shiv and Gauri's shubratiri, Mahen got arrested, Nikila and everyone were waiting for him. Devika walks in and says that 'Mahen babu and you have to break Shiv and Gauri's marraige'. Nikila retorts back saying that 'you have tried this before, it didnt work then and it wont work now'. Now I always thought that was something fishy to say. If Shiv and Gauri's marraige was an accident, how could Devika have known they were getting married and tried to stop it before hand.
Shiv has already confessed to the fact that his marraige to Gauri was planned long time ago. So I think Nikila was in on the whole plan. I still dont know what the reason is but whatever the reason was it wasn't in Gauri's best interests. It could have been for the land or for some stupid kundali reason. But whatever the reason they were using Gauri. That is why Devika is hell benting on breaking this marraige. 👏