Thanks for your message.I've hit such a big brick wall with fining information for the Twining Family in Australia, like you have only got information from family members though we don't have a 'Twining Book'.I would absolutely love a copy of the Family Book you have.
I have yet to find a Hannah Marie Twining in my research so inturn no Swan family. Though I would guess we are related somewhere along a tree branch. But for some strange reason I have heard of Rev WHG Twining, maybe I've come across his name but haven't found the connection to my line as yet.
If I find any connection I will be sure to let you know.