- Little is known about Angelica other than that she was the 'natural' daughter of John Cochrane, brother to the 9th Earl of Dundonald. She appears to have been raised by John's brother the Hon. Basil Cochrane. The Gentleman's Magazine of 1834 records the death of Angelica Hoseason at Bath, stating she was the wife of Thomas Hoseason of Banklands, Lynn, Norfolk, and only sister of Capt N.D.Cochrane RN and Col J.J.Cochrane. 
- Angelicas ancestry is somewhat obscure, as no record of her birth or baptism has yet come to light. In a miniature portrait by the British artist Thomas Hazlehurst, there is an inscription on the inside lid of the original travelling case which suggests, Angelica was apparently the 'natural' (meaning illegitimate) daughter of the Hon. John Cochrane, third son of Thomas Cochrane, 8th Earl of Dundonald. John's brother, Basil Cochrane, certainly left generous legacies in his will to Angelica and her three siblings, Rear-Admiral Nathaniel Day Cochrane, Colonel James Johnson Cochrane of the 3rd Guards and John Cochrane, an Attorney-at-Law in Madras, India. It seems likely that it was the latter brother, John, who was instrumental in bringing his sister together with her husband, for the Madras Courier of 24 August, 1803, records her as having very recently married Thomas Hoseason, a naval officer stationed in the colony.