It is true that Charu won't be dumb and Thulasi can't be smarter than Charu, because psycho will do anything like hurting people, but Thulasi will try to do it on her own way, not hurting anyone including Charu.
But this time Charu can't do much against it because if she does then it means letting her psycho out. This will ruin all her plans as they would only try to cure her. And Thulasi this time is acting exactly like Gutter& Charu, supporting both sides,isn't that what Gutter and psycho did to create fight between hubby& wife. That is why i think she can't do anything smarter than Thulasi. And the situation is favourable for Thulasi.
Moreover like Noxeous said, Thulasi is targeting Charu's good name and future and not really N&L being accepted by the rich family. As long as it does not look like blackmailing for Periyappa, he will agree. He has to come there in today's episode and if he sees Gayathri too worrying about her daughter's future, he will accept them for his SIL and "daughter" Charu's future. My worry is that TA should not open his thiruvaay, if he does, Periyappa will get angry. Thulasi has to shut him again.
If Gokul's words have any meaning, Charu will go with her mom and she will keep quiet until VR is out, then again she will start her cunning game, but again her plans will fail as VR would stop her. The first one to be tortured by psycho would be either her selfish SIL or her romance partner before she starts with Thulasi.
I just hope Kumaran does not decide to drag this part of Charu being in TT's house and gives us a good week including friday's episode!