Anyone with information about Catherine Slater who arrived from London on the 'William Metcalfe' 1837 in Hobart?

I next have her marrying (as a spinster) Samuel PRIESTLY in Sydney in 1840 - but at this stage I believe she already had a child, Henry (surname unknown) born 1838. This birth date is from Henry's marriage certificate, and I can not find it in the NSW BDM or Tas Colonial records.

Any information would be greatly apreciated.

cheers
matt