She was born in 1848 in 1849 in Paddington, London, the daughter of George Paxton and Harriet Elizabeth Fletcher. The family were well-off, for in the first Census in which she was present, 1851, at their Paddington home, they have a servant.
Anyhow, there were literal rumours within the family that she was actually adopted; she had an apparently strained relationship with her parents and my uncle and was almost driven to suicide until she married and had a family of her own (which saved her). These are stories that have been passed down the family tree. I know there is not much concrete evidence there, but i am aware that adoptions (however subtle and under the radar) would have been more common amongst wealthier than poorer families, although wealthier families would have maybe felt more of an ethnical duty to work within the law.
But basically, is there the possibility of finding her birth certificate (which should show the maiden name of her mother?), or do they not go that far back? Obviously, if it does show 'Fletcher' as it, I shouldn't be surprised.