Little is known of her early life or education. Lady Hastings was an avid collector of fossils, specializing in vertebrates. Since 1855 her collection has been housed in the British Museum, containing specimes found in Europe.
The palaeontologist and anatomist Professor Richard Owen wrote of the thousands of fossils previously in her private museum at Efford House, among them "some of the finest in the world".
Her knowledge of local geology, especially of the Eocene, and her meticulous work on fossil remains, gave her an expertise which was respected by scholars. Lady Hastings associated with many eminent scientists during her lifetime, including Edward Forbes, Charles Lyell, Alexander Falconer, William Buckland and Richard Owen.
The geologist Forbes referred to her as a "fossilist" and acknowledged her work. Sixty-four of her letters to and from Owen are preserved in the Natural History Museum"s Richard Owen Collection.
In 1847, Lady Hastings presented her paper to the Oxford meeting of the British Association for the Advancement of Science, exhibiting two crocodile skulls and the shell of a turtle from Hordle Cliff.She argued that crocodile remains found on the Hampshire coast and also on the Isle of Wight showed that the area of the Solent had been a freshwater river or lake.
Immediately after Richard Owen explained that the remains from Hordle suggested "a new genus of Pachyderm", which he named Paloplotherium, falling between Palaeotherium and Anoplotherium, during his presentation of the same fossils. In 1852 and 1853 she published papers on the stratigraphy of Hordle Cliff (which she called the Hordwell cliff), the first such accurate accounts of lieutenant She stated that her goal was to provide local information from which a comprehensive account of Tertiary stratigraphy could be created.
In 1858 she died in Rome and is buried there.