hi lucy, it was on a grandaughter of emily's birth cert in 1894 (for the descrition of informant bit), it says, 'agent duly authorised in writing by emma snook who was present at birth', i doubt they have kept the writing at bdm as i know prior to 1972 they had not kept evidence of registrations as the bdm lady told me. ex:, when i got grandads birth (he wasn't regd til he was 30yrs old in 1950) there was a signed affidavit but that was not kept and that is when the bdm lady said about eveidence like that not being kept, so i guess we may never know as on other certs emily's mark, signature is a x!!