Agree that Sayali's accent is not in tune with the local dialect. It is a bit distracting. But the story is about Vidhi-Pushkar and there they don't need any words, do they? They are just using the language of their eyes.
Anyway, if you see,even Rajashree has a pronounced south Indian accent. Pushkar, his sister and Urvashi also have a very neutral accent and is no way like the language used by Jijosa, maasa or Rangeela.
IMO the story will soon move to the Rathod palace after marriage and there I think the accents will become irrelevant (whether it is in Rajasthan or any North Indian city) as their drama will become the centre point.