pekarokiki on Family Tree Circles

I have come up against a brick wall for my great great grandfather George Henry Chillingworth - he was born c1839 in Lambeth, Surrey to Richard Chillingworth b bet.1816-1821 and Caroline Evans from Gravesend in Kent (I have her surname as her mother was living with them in 1851). I have the family on the census returns and have found the BMDs for George Henry's siblings but can find no Birth register for George, nor can I find a marriage register for Richard and Caroline - oooooooooh???? I'm now thinking that maybe they weren't married at all (not a problem) but, I know George Henry was born - but where, when etc etc etc.
If there is anybody out there that can throw some light on this, please please - I would be eternally grateful.