Robert was born c 1828 at St Brides Pembrokeshire
I’m afraid there is no Robert Herbert baptised at St Brides in circa 1828, there are two Herbert baptisms at St Brides, I note one in 1835 and one 1833.
The IGI expands on this to read
Mary Anne Herbert baptised 16 Jan 1835 to William & Mary Herbert
Elizabeth Herbert baptised 21 Apr 1833 to William & Mary Herbert
There are no Herbert mrge’s at St Brides that would equate to the above, and the only mrge that appears to equate is a William Herbert to Mary Davies in 1834 at Pembroke St Mary. I can supply full details of this mrge if it ever appears to be the one you are after.
I note the burial of a John Herbert at St Brides in 1837 and a Mary Herbert buried in the same location in the same year.
Rgds
Orielbenfro