Kitty Hunter’s ancestor Sir Charles Somerset (died 1599) has a male-line descent from Edward III.

                                       Edward III 
                                        |
                           +------------+-----------------------------------------------------+ 
                           |                                                                  |
                          John of Gaunt                                                      Lionel Plantagenet
                           |                                                                  |
              +------------+---------------------------------+                               Philippa Plantagenet
              |                                              |                                |
             1st Earl of Somerset                           Joan de Beaufort                 Elizabeth Mortimer  
              |                                              |                                |
 +------------+-----------+                        +---------+--------------+                 | 
 |                        |                        |                        |                 |
Joan Beaufort            1st Duke of Somerset     1st Earl of Salisbury    Eleanor Neville   Henry Percy
 |                        |                        |                        |                 |
 |                        |                        |                        +-----+-----------+ 
 |                        |                        |                              | 
James II of Scotland     2nd Duke of Somerset     1st Marquess of Montagu        Ralph Percy 
 |                        |                        |                              | 
Mary Stewart             1st Earl of Worcester    Lucy Neville                   Margaret Percy 
 |                        |                        |                              | 
1st Earl of Arran        2nd Earl of Worcester    Elizabeth Browne               Guiscard Harbottle 
 |                        |                        |                              | 
Jean Hamilton             +------+-----------------+                             Mary Harbottle 
 |                               |                                                | 
6th Earl of Glencairn           Sir Charles Somerset                             Sir Edward Fitton
 |                               |                                                | 
 |                               |                                               Sir Edward Fitton  
Elizabeth Cunningham            Elizabeth Somerset                                | 
 |                               |                                               Sir Edward Fitton 
 |                               |                                                |
Jane Craufurd                   Sir Charles Gerard                               Penelope Fitton
 |                               |                                                |
 |                               +------+-----------------------------------------+ 
 |                                      | 
Elizabeth Craufurd                     1st Earl of Macclesfield 
 |                                      |  
James Hunter                           Charlotte Gerard
 |                                      | 
Robert Hunter                          Elizabeth Orby
 |                                      | 
 +------------+-------------------------+ 
              | 
             Thomas Orby Hunter     
              |                                                   
             Kitty Hunter == 10th Earl of Pembroke (affair)
              |              descendant of Edward III    
              |
             Augustus Reebkomp

Thanks to Mark Humphrys (www.humphrysfamilytree.com)