Looking for Other Children OR Details Re George Smith C 1827 Married to Sarah Goodwin C 1835 Married St Giles Applegate London on 1st Jan 1852

My Great grandfather was John Robert Smith b St James Clerkenwell 14th Sept 1855 at 21 Albian Place Clerkenwell. Birth registered 24th Oct 1855 and mothers name shown as Goodman rather than Goodwin.
I would be interested to hear of other children or information re this Smith family as John Robert emigrated to NZ. Other family decendents had a different set of parents etc but we had Clerkenwell and his birthdate written down by our grandfather so believe it to be true and John Robert was also a butcher like George.
Thanks in advance