Hi Louise,
The 1861 census for London that I have is only partial as it has not all been transcribed as yet.
I found a Mary Kelly aged 1 but no Montague or Emma, so that doesn't fit.
There is a family of Killey at St Giles in the Fields but not for your christian names.
I will keep a note of the names as I am transcribing and if I come across them will let you know. I only have mot of Shoreditch and one section of Southwark that I have done and they are not in that area. Sorry, Sue