I saw the same pattern today. I remember Urmila being so nervous and scared that the kids bought the cake for Gopi's birthday, and before anyone could say anything else she blurted the truth that she was trying to hide by hook or crook, herself. She was so scared that if Koki found out from someone else, she would eat her alive.
I see same happening to Rashi. She is scared and nervous that Sonal will say something that may incriminate her. At the rate she is going, if Sonal comes in front of the Modi family, Rashi will blurt everything out of her own mouth, before Sonal could even greet anyone.
I am hoping this is where its leading, since Sonal really doesn't know that Urshi played Jigar and her.
Now that would be poetic justice.