In 1517 [her father] William Sidney (age 35) and [her mother] Anne Pakenham (age 32) were married.
In 1531 Frances Sidney Countess Sussex was born to William Sidney (age 49) and Anne Pakenham (age 46) at Penshurst Place, Kent [Map].
On 22 Oct 1544 [her mother] Anne Pakenham (age 59) died at Penshurst, Kent [Map].
On 11 Feb 1554 [her father] William Sidney (age 72) died at Penshurst, Kent [Map]. He was buried at St John the Baptist Church, Penshurst.
Before 1555 [her future husband] Thomas Radclyffe 3rd Earl of Sussex (age 30) and Elizabeth Wriothesley (age 19) were married. She the daughter of Thomas Wriothesley 1st Earl of Southampton and Jane Cheney Countess Southampton 1509-1574 (age 45). He the son of Henry Radclyffe 2nd Earl of Sussex (age 47) and Elizabeth Howard.
In 1555 Thomas Radclyffe 3rd Earl of Sussex (age 30) and Frances Sidney Countess Sussex (age 24) were married. He the son of Henry Radclyffe 2nd Earl of Sussex (age 48) and Elizabeth Howard.
On 17 Feb 1557 [her father-in-law] Henry Radclyffe 2nd Earl of Sussex (age 50) died. He was buried at St Lawrence Pountney Church. His son [her husband] Thomas Radclyffe 3rd Earl of Sussex (age 32) succeeded 3rd Earl of Sussex, 12th Baron Fitzwalter. Frances Sidney Countess Sussex (age 26) by marriage Countess of Sussex.
Around 1572 Steven van der Meulen. Portrait of Frances Sidney Countess Sussex (age 41).
In or before 1573 Thomas Mildmay (age 33) and [her sister-in-law] Frances Radclyffe were married. She the daughter of Henry Radclyffe 2nd Earl of Sussex and Anne Calthorpe 2nd Countess Sussex (age 51).
In 1578 [her brother-in-law] Egremont Radclyffe was executed at Namur.
On 09 Jun 1583 [her husband] Thomas Radclyffe 3rd Earl of Sussex (age 58) died. His brother [her brother-in-law] Henry Radclyffe 4th Earl of Sussex 1532-1593 (age 51) succeeded 4th Earl of Sussex, 13th Baron Fitzwalter. by marriage Countess of Sussex.
On 09 Mar 1589 Frances Sidney Countess Sussex (age 58) died. On 15 Apr 1589 she was buried in Chapel of St Paul, Westminster Abbey [Map].
Thomas Fitzwilliam and [her mother] Anne Pakenham were married. He a great x 4 grandson of King Edward III of England. 
Paternal Family Tree: Sidney
Maternal Family Tree: Anne Pakenham 1485-1544
Great x 1 Grandfather: William IV Sidney
GrandFather: Nicholas Sidney
Father: William Sidney
Great x 2 Grandfather: Robert Brandon
Great x 1 Grandfather: William Brandon
Great x 2 Grandmother: Ada Calthorpe
GrandMother: Anne Brandon
Frances Sidney Countess Sussex 1531-1589
Great x 1 Grandfather: John Pakenham
GrandFather: Hugh Pakenham
Mother: Anne Pakenham