Benefidia Silva ROSA [????-????]

I am trying to find an ancestor.  Her name was Benefidia Silva Rosa.  We know she had a child Bartolomeu, who was baptized in the Cathedral in 1851.  The father was listed as Antonio d'Eça vaz Bernades. This much is documented in a study of the Macanese by Dr. Jorge Forjaz a few years ago.

I wrote to the H.K. Government Dept. of Birth/Deaths and they just informed me that there are no traceable records prior to 1873. I also emailed the Cathedal but have not received a response of any value.  Can anyone help please?  Our family is willing to pay a researcher or make a donation.  We are very anxious to get any information.