In the beginning when the two Jigar and Aham got married Hetal saw how bad Kokila was dealing with Gopi and Rashi, the gold incident, if you watch again when Kokila went to buy that huge necklace and pendent and gave to Gopi to wear and Gopi gave it to Rashi when she admired it, Rashi put it on and was admired more, Kokila couldn't stand it and shouted a Gopi so much, Hetal said both are the same if one wears it and other doesn't it's the same, both are sisters and bahu's of this house, but Kokila at that point had started the competition of them two and Hetal recognised Kokila's action.
Of course Kokila punished Gopi by putting every single gold set on her, so Gopi next time does as she is told by Kokila and doesn't think by herself to do anything.
I think Hetal because of that day and what happened subsequently, Gopi can cook, Rashi can't the comparisons constantly, your bahu isn't as good as mine...as a result no matter what Kokila says about Rashi Hetal feels it's a slight, a comparison between Gopi and Rashi, and she defends Rashi as she doesn't want the competition that Kokila started with the two girls.
I believe Hetal does live in a dream world, but she just wants peace and love in the house, and not noise caused by Kokila and her big mouth.