Hindi TV Serial - Behnein on Star Plus - the fight of 4 sisters against many odds

As usual, for any serial, there has to be drama, there has to be intrigue, there has to be relatives plotting to steal money and property, and there has to be tension between a daughter-in-law and mother-in-law, with the husband getting stuck in between.
In the case of this serial, it is a serial that takes the life of 4 sisters, whose parents died in a fire caused by a short circuit. However, this fire would not have taken their lives, except for the case of the aunt of the girls, their father's sister, who hid the key to the room in which the parents were. The sister, Nimma Fai, had decided that the fire should let the parents die, and so it happened when the parents die. Now she wants the sisters to get married off so that she can take the property for herself.
The sisters are basically straight, but it is not necessary that all of them are fully strong, as the second eldest sister Smriti is weak in the head, and this gets further enhanced when her mother-in-law hides the medication she needs. Smriti has given birth to a baby Prem, but when it seems that her mental health could cause problems, her mother-in-law Kamini forces her to go to a mental health institution; at this, eventually the husband, Mihir would be marrying another girl Mansi to give care to Prem. However, Mansi is after his wealth, and to prevent this, Smriti's elder sister (Purvi) married Mihir (one wonders how she could get married since Smriti's marriage was not dissolved) to the shock of Amar, with whom Purvi was supposed to be married to.