Louisa's father is given as David Evans (deceased) labourer and she lived at South Street Pembroke Docks.
Given that it can be acertained as best as possible that Louisa was born in 1852, and there is only one GRO entry for the year for this area, then a punt on the certificate of Louisa Evans Pembroke Reg District Vol 11a Page 561 will probably be the only way forward.
Research suggests she was either not baptismed or that she was admitted non-conformist, in either case it is doubtfull that an entry will be found for her with her father.
There is one option left ~ a David Evans mrd in the Pembroke Reg District (poss P.D. St John I will check) in the 3rd qtr 1852, which leaves the way open that Louisa was a natural child not born with the surname Evans but took his surname after her mothers mrge to David (vy common occurance), this would of course negate the above birth of Louisa Evans. Take a pin close your eyes and make a choice !!
The more lightly event is that your David Evans mrd in the 4th Qtr of 1846 in the Pembroke Reg Dist. From my parish register transcriptions, I can confirm this mrge did not take place at Pembroke St Mary or Pembroke St Michael so will check P.D. St John.
I know this sounds all rather speculative, lets hope the parish/chapel registers reveal something more.
Rgds
Orielbenfro
ORIEL a welsh window on a surname