Original: Catherine gave birth to her only child - a daughter , Mary Seymour - on 30 August 1548 , but Catherine died only six days later , on 5 September 1548 , at Sudeley Castle in Gloucestershire , from what is thought to be puerperal fever or puerperal sepsis , also called childbed fever .
Simplified: She gave birth to their daughter , Mary , at Sudeley Castle on 30 August , 1548 , but she did not recover from the birth and died soon afterwards on 5 September , 1548 .