Mary Anne Brooks

I am trying to trace Mary Anne Brooks who gave birth in Grahamstown

to Agnes Anna Brooks aprox. Oct. 1875

Agnes Anna Cook nee Brooks is my greatgrandmother. She died 22 June 1930 aged 54 years and 9 months

I am wondering if Mary Anne Brooks is the daughter of Mary Anne Midilet Wicks SM (1820 Settlers)
This would require the Birth record to verify but online I cannot find many records from Grahamstown for this period

I would appreciate any info

Maria Stettler