At the death , on 8 May 1768 , of her brother and only sibling , the prince de Lamballe , Marie-Adélaïde became heiress to what was to become the largest fortune of France .
At the death , on 8 May 1768 , of her brother and only sibling , the Prince of Lamballe , Marie Adélaïde became heiress to what was to become the largest fortune of France .