Individual Details

Caroline Birley was born on November 16th 1851 at York Place, Oxford Road, Manchester. She was the daughter of Thomas Birley and the niece of Hugh Birley MP and of Herbert Birley, for many years chairman of the Manchester School Board.
In 1857 the family moved from York Place to Highfield, Heaton Mersey. In 1864 they moved again to Hart Hill, Pendleton. It was in 1864 that Caroline's interest in geology became clear, as she began her subscription to The Geological Magazine. She remained at Hart Hill until 1884, when she moved to 4 Seedley Terrace, Pendleton. In 1887 the British Association for the Advancement of Science held a conference in Manchester. Caroline attended and became a member. In 1888 she became a life member, and appears to have attended every annual meeting up to her death.
Between 1887 and 1905 Caroline made many trips abroad, often for the purpose of collecting geological specimens. Her trips included:

January 1887 - Egypt
June 1887 - Cortina
July 1888 - Faxe, Denmark
May 1889 - Faroe Islands
May 1890 - Faroe Islands
July 1891 - Faxe
November 1891 - Malta
November 1892 - Algiers
November 1893 - Corsica
August 1897 - Canada
April 1899 - Azores
April 1902 - Boulogne
July 1905 - South Africa

The material she collected all went into the museum she created in her garden at Pendleton. This was called the Seedley Museum and she opened it to members of the public in 1888.
In 1895 she made out a will, leaving the majority of her Mineral and Geological collections to the British Museum of Natural History. She instructed the museums relevant keepers (Mr L Fletcher and Dr H Woodward) to select the material they wanted from her collections and to pass the rest to The Manchester Museum. She also requested, though not making it a stipulation of her Will, that the material was labelled as belonging to the Caroline Birley Collection.
In addition there were a small number of bequests to specific individuals.

In 1896 she moved to London, returning to Pendleton shortly before her death from influenza on February 15th, 1907.

This is the little I've discovered. Although Caroline's will states material should have gone to the British Museum or to Manchester, it seems parts of the collection were also offered to the museums at Bolton, Bury, Rochdale and Warrington, as well as to the Manchester Grammar School museum. In the case of Bolton, Mr L. Fletcher of the British Museum, along with Mr F.H. Birley, arranged this. Unfortunately, this makes it very difficult to estimate the total size of her collections.
The material we hold in Bolton covers more than just the localities I mention above, and I assume Caroline made other trips I have no record of. She also did a large amount of collecting in Britain.
As far as I can tell her love of geology started young and was very much individual to her. Certainly, there is no indication of any members of her family sharing her interest.

The majority of collectors at that time were generally independently wealthy men and clergymen. This makes Caroline's collections all the more notable.

Link to the Bolton Museum website: http://www.boltonmuseums.org.uk

Birth	16 Nov 1851	Pendleton, Manchester, Lancashire, England
Christen	12 Jun 1852	Cathedral, Manchester, Lancashire, England
Death	15 Feb 1907	Kensington, Middlesex, England, United Kingdom

Father	Thomas Hornby Birley J. P. (1815 - 1885)
Mother	Anne Leatham (1820 - 1866)
Sibling	Anne Katharine Birley (1845 - 1923)
Sibling	James Leatham Birley (1847 - 1866)
Sibling	Francis Hornby Birley J. P. (1850 - 1910)
Sibling	Walter Birley (1852 - 1852)