No, there's nothing to suggest any cheating here.
My understanding is that in weight-classed combat sports, everyone struggles to "make weight" before the match -- through dehydration, caloric restriction, aerobic activity, etc. After you make weight, you're completely free to hydrate, eat, etc. before the match itself. And everyone does, because why would you want to compete while you're dehydrated and under-energized?
But if you then have another match very soon after the first one, and there's another weigh-in for the second match, you now have to make weight again -- through dehydration, caloric restriction, aerobic activity, etc.. And here, the Indian wrestler made weight on the morning of the first day and won three matches later that day. She then had to make weight again the very next day, and scrambled to do so. But she ultimately came up short, missing by 100 grams. To reiterate, there's nothing to suggest any cheating here, just a failed attempt to make weight.
She was only over the weight limit by 100 grams, couldn't she just let out a little bit (100cc) of blood to get under the limit? For standard blood donations, people give 450cc of blood.