One of the people who has most intrigued me has been Caroline Weiss (and also her sister Benigna). I know from Caroline's portrait that she reached adulthood - whereas I can't be sure of this for Benigna. So I was left wondering "Where did she go?" It was possible that one of the reasons why she couldn't be found was that her surname might have changed through marriage.
One useful website that I have found for the Weiss family has been Families in British India Society (FIBIS). They have quite a lot of records in their database of baptisms, marriages and deaths and other such things related to the British living in India and South Asia between 1600 and 1947. I found Caroline's mother's burial details on the FIBIS database. I have also recently found a few useful things on the new FamilySearch website, which I have previously found rather hit-and-miss. I don't always trust everything I find on the FamilySearch website but sometimes when you have nothing else to go on... I found Frederick and Egmont's baptism records from Aden on this website - I had known that Frederick was baptised in Aden, but was unaware that Egmont was also.
What I knew of the family was that the children were all born in England and then sometime during or after 1841 they and their mother followed their father to India who was stationed there with the British Army. When both their parents died in 1845, the boys were apparently sent to military school in India, and the girls supposedly sent home to England for their schooling. But I could find a record of Adelaide, Caroline's eldest sister, back in England, but nothing for Caroline (nor Benigna). I had an impulse to check if there were any records for the children in India. I searched the FIBIS database for "Caroline Weiss". One record came up - a listing in the Bombay Almanac of 1853 - for a marriage announcement for Henry Richard Hughes, an engineer in the Indian Army, to Caroline J. Weiss of Kotree (Kotri), married 23 Dec 1851 in Bombay. If this was my Caroline she would have been 18, and I would have expected her to have at least one middle name because those of her siblings who we have good records for all have one or two middle names. And I knew Frederick, her brother, had definitely lived in Kotree. It could be her...
I then looked on FamilySearch to see if this Henry and Caroline had any children. Mary Adelaide Hughes was born to Henry Richard and Caroline Judith Hughes in 1862 in Kurrachee (Karachi, then in India). Adelaide was the name of Caroline Weiss' eldest sister... It's not far-fetched to think she might name her daughter after her sister. There was also a Henry James Hughes born in 1865 in Kurrachee. There is also a record for an Annie Hughes born 1869 in Kurrachee. I'm not so sure about this record - there's no middle name, plus, as I subsequently discovered, the Hughes were possibly back in England by this date. They had a daughter Elizabeth recorded living with them in the 1871 Census (with son Henry there too, but no Mary) who was born around 1868 in Blackheath, Kent. Perhaps this is where they first were after they arrived back in England. Henry Richard died 7 Feb 1782. By the 1881 Census only one child was living with Caroline - Marion Constance, who was apparently born the same year her father died.
Caroline Judith Hughes died 6 May 1905 in Bath. I have not been able to discover what happened to Marion after her mother's death, however it is possible that she did not marry - she was still a spinster at 30, which is a long time to be left on the shelf in those days. Neither have I found any death records for any of the other children.
The two things that make me think this is Caroline Weiss, daughter of Charles and Benigna, are (1) she was noted as from Kotree in the wedding announcement, and I know that her brother Frederick lived in Kotree until he moved to England, and (2) her first daughter's middle name was Adelaide, which could be after her eldest sister Adelaide. It's all quite circumstantial but that's the best I've got to offer at this stage. Perhaps her marriage certificate, if I could get a copy, might give her parents' names, or maybe the name of a marriage witness might provide a clue, but perhaps I'll never know.