There are already a few examples of sharing variables via memory on this forum but you may like this one.
There are 2 scripts:
1. Example_Sharing_Memory_Var.au3 is the calling application (I call it the mother application)
2. Sharing_Memory_Client.au3 is the client application
The mother Application is creating the structures for the different variables to be shared across applications (could be more than 2 of course)
Once the structures are defined and assigned, the child application