I always thought that Sonal is like her father but after watching a few eposides I see that she same but uses a different approach.
She is friends with her cousins to keep tabs on them and also to see what they are up to to.
On rakhi day when Shanti gave her lots of money and only little money to Nimmi and Preeti she said what can I do and left for collage.
When Rani returned and face her money for breakfast she was really eyeing it and knowing that she does not have much money.
Now taking the Scooty without Riya permission and she took it and ran.
She is the same as the rest of them.