Hi Ray,
Forgot to ask if you've used the Search facility to check for Phoebe Searle on the Hertfordshire boards?
I did and several posts regarding a Phoebe Searle came up, of course I can't say if any or all are your Phoebe Tearle.
By the way my maternal grandmother was an Essex Searles, a sibling of one of my Searles ancestors, Henry Searles was baptised 19 Feb1797 in Felsted, Essex, Henry married a Mary Wright in 1820 in Sawbridgeworth and started a Hertfordshire line.
Regards.