In fact it turned out that there was no mysterious Colonel Hallows. The family story, which claimed Hallows was a Colonel in India, and left his wife and family well off following his death, was inaccurate although not without foundation.
Mary Elizabeth Hallows, 2nd great-grandmother to my first husband James A Andrew Baker, was the daughter of Thomas Hallows and Sophie Jenour.
Sophie was born in Carnpore, India in about 1820 and it is very likely that her father was a lieutenant Thomas Jenour of 14th Buckinghamshire Regiment, 2nd battalion. Her marriage certificate shows that her father was indeed Thomas Jenour, although by the time of her marriage his occupation was scripture reader and not an army officer.
There is a pallots marriage record of Thomas Jenour's marriage to Mary Cole in Newport, Hampshire on January 19th 1813 and also a record of him passing through Malta in 1810 either travelling to or returning from India.
Assuming that the family account of an ancestor who was an officer in the British army, serving in India is correct, then from the information gleaned from the records, this is the most likely explanation.
As for being wealthy, Thomas Jenour was probably the son of Joshua Jenour a once wealthy London newspaper publisher, although he reputedly spent his vast fortune and left his family improverished. However, improverished is probably a relative term and to their neighbours in the north west of England in the late 19th century Sophie Hallows, his daughter, may have seemed to have more comfortable means than most. However, at the time of writing I have no evidence one way or the other about their financial or social status.