I highly doubt Princess Margaret left a 30 million pound estate. She never was loaded because George VI, as is tradition, left the majority of his fortune to Elizabeth as the new Sovereign, with a sizable amount set aside for The Queen Mother's benefit.
In addition, it's been documented quite extensively over the years that The Queen privately financed many of Margaret's expensive indulgences, so I don't think there is a big amount of cash waiting for her children.
In addition, it's been documented quite extensively over the years that The Queen privately financed many of Margaret's expensive indulgences, so I don't think there is a big amount of cash waiting for her children.