Sarah Maynard's baptism record? :
https://www.ancestry.co.uk/interacti...=successSource
St Olave, Bermondsey, Southwark
Christenings November 1797
Sarah D of Thomas & Mary Hayward Button Maker B[orn] October 16, [baptised November] 12.
It definitely says Hayward on the image but Ancestry have transcribed it as Maynard. But because you say the father's occupation is button maker, it seems to fit despite the year being wrong? Of course it could easily have been written down wrong on the register as it was likely copied from another document.