She was born 24 Apr 1558 in Shirwell, Devonshire, England  Father named as John Chechester in the Findmypast transcription.
Many sources agree that she was born in Shirwell, Devonshire, April 24, 1558. One source says she was christened April 26, 1558 in Stirwell.
Her surname is most commonly seen as Chichester but has also been seen as Cichester and Chechester. 
Her given name appears as Urith, but Sir Alex Chichester in his 1871 genealogy refers to the the 16th child of John and Gertrude Courtenay Chichester and wife of John Trevelyan of Nettlecombe as "Ursula." 
She married John Trevelyan of Nettlecombe in Somerset. 
Her marriage was arranged by an indenture dated 6 May (Elizabeth 10) 1568 between the two parents. 
The indenture conveys the following information:
Names of fathers
John Trevylian of Nettlecombe, Esq, County Somerset. He had a brother named Edward. 
Sir John Chechestre of Rawleigh, Devon, Knight.
Assuming a birth year of 1558, she would have been aged 10 at the time, and the marriage itself would have followed at a later date.
A likely actual marriage might be that shown on 20 Apr 1576 in Shirwell, Devon to John Trevillion Urith would have been aged 18 at the time.
An alternate marriage date of 15 May 1591 in Nettlecombe, England is sometimes seen. 
This is suspect, as Urith would have been aged 43 at the time.
One source gives her death date as 1591 in Nettlecomb, Somersetshire, England  However, the children linked to her on WikiTree were born during the period 1583 and 1608. If these birth years are correct, her death would have occurred after 1608.