Hi, Was your half sister adopted . If so - do you know when / where - at birth or ?
If so -Perhaps you can search for / register - to find your sister.
You know your sister was born at the Royal Alexandra Hospital in Edmonton
They may hold some information - archived - perhaps not on site - may be worth making a request
A posting many years ago - stated that hospital keep a ledger for the floor - where information is entered - when the ledger is completed it is archived - This information may be available
Register with the Govt of Alberta - dept - re Adoptees - parent search - you may make a connection