Hi Greg have just had another look at one of my books that I had researched a long time ago and have found this:
At Great Chishall Ann Walters baptised 21/2/1779 daughter of STEPHEN and SARAH

HEYDON ESSEX - STEPHEN WALTERS of this parish SARAH WEBB Great Chishall by banns single 1st February 1778 Witness Wiliam Pitty and Richard Drayton

So I finally have the right Ann to go with Robert - now all I have to do is find out who Robert was born to and I can make a start. I am still trying to find this out as I type this to you - many thanks again = Kelly