Cache is located at S 33 2A.BC1 E 149 3D.EF1
The following audio has the answers for the missing co ordinates
https://www.bathurstregion.com.au/contact-the-visitor-information-centre/in-the-news/podcast/bathurst-pillars-episode-16-mary-black/
A= Female factory in Bathurst opened in 18A3. Add 1 to answer
B= Mary Black arrived in Australia in 18B0 Add 7 to answer
C= Mary Black married in 18C9. Add 2 to answer
D= Walter Black began working for George Ranken in 18D2. Add 1 to answer
E= First time Mary Black refers to herself as a widow 183E. Add 2 to answer
F= Mrs Black died at the Royal Hotel in Bathurst in 18F3.