(Far left) Roger (Rolt) Wheeler (nephew) | Mary Ethel (Rolt) Wheeler | Joseph Wheeler (Father) | Amina Wheeler (Mother) | Francis (Rolt) Wheeler (Brother)
Taken c. 1910
Rolt was added to the family name as a pen name to make it unique when published. Both Ethel and Francis, also an author, used the name and it went on to become adopted as the family name of Roger and his descendants.
You can read more about Francis Rolt Wheeler here http://fr.wikipedia.org/wiki/Francis_Rolt-Wheeler