I can understand why choti ma doesnt want RR to get married coz she doesnt want Rags to go through the same thing that i think she went through wen she got married to the youngest son in the family where there was already a gori chitti bahu for the older son.
Her saas might have treated her bad by being partial towards Vasu....and always taunting her.
Her husband might not have been able to protect her from society or her mom's bad behavior....thats y on 13 oct's episode he says...."i know Ranvir loves Ragini and he'll keep her happy.....coz this time nothing wrong will happen as he is Ranvir and not Satyenda."
Poor Choti Ma....she faced the same problems and does not Ragini to face the partial differences and her comaprison with Sadhna all the time.