I found George Hodgson in Scammon on the 1910 census, which puts his birth around 1860.
If Alice's age is right on the 1911 Scotland census and the travel documents, her birth is around 1872.
Thinking outside the box, Alice and George may not be together as siblings on the 1881 census due to the 12 year age difference.
By 1881 he might have left home already.