FreeBMD has the following Deadman birth registrations from 1901 to 1911:
June qtr 1902 Elizabeth Agnes Deadman
December 1903 Dorothy Deadman
September 1906 Annie Charlotte Deadman
December 1908 William John Deadman
December 1910 Edward A Deadman
June 1911 Albert Deadman
The following deaths are also noted:
September 1903 Elizabeth Deadman age 1
December 1903 Dorothy Deadman age 0
According to the 1901 census, there is only the one adult George Deadman in Oxfordshire, so it's pretty likely the children mentioned above are his.