I always thought Madhu will be very cautious while dealing with dipali.
I hoped Madhu would remember that while dealing with people like Dipali every word is important and every matter had to be dealt sternly.
I hoped Madhu would realize that Dipali is doing mischief at the moment when her saree was purposely stained by Dipali and she tried to be too good and offered Madhu her saree.
I wanted Madhu to be good and stern with dipali.
Madhu has to remember that she is dealing with a worst kind of human being who is her cosister.
Dipali's main plot is to humiliate Madhu in front of every one during Puja.
Since Dipali realized that RK will have nothing to do with her she will see to that RK and Madhu get separated. Dipali is very jealous that Madhu and RK are coming closer(though both of them will not admit this)
According to Dipali if she will not get RK, Madhu should be separated from RK by all evil desings. This is the begining of the game plan of Dipali.
Madhu without realizing what dipali is upto walked straight into her plan and wore the saree given by Dipali.
If madhu were to have gone down in that saree for Puja Dipali may accuse that Madhu stole her saree and jewels and humiliate her infront of her mother, malik and all family members and guests.
Even though RK will not tell the reason why he wanted madhu to change her saree, it is for Madhu's own good that she should change her saree and go down with RK to perform Puja.