Hi, your 1/2 sister might now be aware of the circumstances - Do you know if she was put up for adoption.?
If she stayed with her birth mother - she may eventually have been made aware of the name of her birth father Grant A. TOWNSEND
Some Provincial Govts - now allow access to adoption papers - as well - have registries for adoptees - and families - to make a connection.
You have posted to the Message Board for KIDS - Perhaps it would be best if you posted to the message board/s - for Ontario - where the daughter was born -
General Message Board for Ontario - will cover all
http://boards.ancestry.com/localities.northam.canada.ontario...Wallaceburg is in the Chatham -Kent area
http://boards.ancestry.com/localities.northam.canada.ontario...Do you know the name of the mother - or the names of her parents ?