Shemeska
Adventurer
Technically, while Birthright itself did not reference the connection (at least as far as I know), Spelljammer did. Aebrynis was located within the Bloodspace crystal sphere, which can be reached by following a phlogiston flow from Greyspace. And since Spelljammer mentions it, it means it is also canonically a part of Planescape, and thus within the Great Wheel.
I can think of a number of references to Aebrynis within Planescape sourcebooks as well.