https://www.indiaforums.com/article/sharmistha-turns-evil-blackmails-raginilakshya-in-swaragini_91842
Now, here is another article saying that it will be Parineeta who would do so to avenge Ragini's slap. Here is the another link:
https://www.indiaforums.com/forum/swaragini/4648217/tc-article-revelation-slap-blackmail-and-more-in-colors-swaragini
Now, which one is the right news since both the sources are considered reliable.
I think it will be Parineeta who would do that as this woman is hell bent on keeping her so called position & izzat in the house right now. But then this is a show & anything can happen.
All of a sudden this show is all about either introducing grey shaded, evil characters (Kavya, Sanskar's ex gf, Sahil,etc) or about making every original lead characters grey shaded & evil one by one (DP, Sanskar, Ragini, Adarsh, Lakshya, Parineeta & so on) and then show their good shades in the later episodes..