Colonel Edward Walter Trevor whom you are looking for is definitely connected.He is the younger brother of my 2nd great grandfather Major General John Salusbury Trevor CSI, and also younger brother of Victoria Cross winner (in Dewan Giri) Major General William Spottiswoode Trevor.....all of whom were the sons of Mary Spottiswoode, daughter of the Laird of Glenfernate, William Spottiswoode, and Captain Robert Salusbury Trevor, who was assasinated in Kabul in 1841 along with Sir William Macnaughten.
Mary who was pregnant with her eighth child, and her seven children under the age of ten, survived the tragedy of 12,000 Britons dying in the march out of Afghanistan through the Khyber Pass....because they were handed over to the Agbar Khan and spent nine months as hostages before being rescued by General Pollock.
All five sons returned to India, John, William, Salusbury and Edward all signed up as Addiscombe Cadets and went out into the army (John and William as engineers...have to check about the other two)...whilst the youngest son, Arthur Charles Trevor instead went into the civil service in India, and later became Sir Trevor.Mary's boys did her proud...at the end of her life she would have been able to boast she had two colonels, two major-generals, a knight and a Victoria Cross winner.(Her two surviving daughters [the baby born in captivity died in 1842] married well within the same class, one was the mother of the last Governor of the Punjab, Edward Norman Baker, and the other married a major-general).
I have hit a bit of a brick wall in my research (because I am in Australia...and all their records are in the British Library in the Oriental and India Office records)....but I certainly have death and burial details of Edward...but not of his wife.....and there is a marble monument in Kensal Green cemetery erected by the boys in memory of their father to whom subsequent entries then record their mothers death, and each of the children......
If you email me directly with myname @ah.inspired.net.au....[broken here so I don't get automatic spam]....I will email you the finer details of what I know.(The Trevor's go way back to Tudor Trevor in the 1100's.....and the Spottiswoode's way back too...)
Cheers (the other part you'll need for the email is myname: sharoncasey)