Brian's index doesn't go beyond 1900.

You'll need to study the films of the births available thru the British archives, the Manx Museum or thru the Mormon Family History Library unless you run into someone who has access to any of the above or who has the info in their files.
There is a process whereby you can send for records that is explained somewhere on this board--use search function.
You can also hire researchers on the island, I believe.

Where did Georgina and William live and die?

I don't see any IOM burial records for them.

Donna