thank you to all of you who have been answering my killey posts and helping me out.
I went to the ids place today near the albert hall. I didnt find out a lot, mainly because the marriages don't include the fathers names....but at mary killey (1812)'s marriage to thomas cashen, one of the witnesses was john killey, who could be her father john or her brother john (1810), who was also the son of john killey and mary callow. so this makes mary being my mary a bit more likey.
my 3x great grandfather william (1814) married in 1838 so there was a proper certificate and on it he names his father as john killey.
the marriage of john killey to mary callow in 1804, says he is a bachelor of this parish (patrick) and she is a spinster of german. (so she wasnt a widow and I am no nearer finding out when she ws born and who her parents were! the witnesses were william white and david quayle.
.......so, I dont have a lot more info but I have checked to see.....just wanted all my helpers to know that I have been off sherlocking.....and the info is now here for anyone else to look at at a future date.

if anyone stumbles across anything else....dont hesitate to get in touch!!!

big fat thanks. love jane