+———Joseph WILKINSON (abt 1846 – )
      |
  +———Robert CROSSLEY (1877 Preston, Lancashire, England – )
  |   |    
  |   +———Harriet SINGLETON (1851 Penwortham, Lancashire, England – 1907 Preston, Lancashire, England)
  |    
  Robert CROSSLEY (1907 Preston, Lancashire, England – )
  |    
  +———Margaret Ellen HOLKER (1879 Preston, Lancashire, England – 1956 Preston, Lancashire, England)