Wikepedia says:
In March 1617, Rolfe and Pocahontas boarded a ship to return to Virginia, however, the ship had only gone as far as Gravesend on the River Thames when Pocahontas became gravely ill. She was taken ashore and died. It is unknown what caused her death, but theories range from smallpox, pneumonia, or tuberculosis, to her having been poisoned.According to Rolfe, she died saying, "all must die, but tis enough that her child liveth." Her funeral took place on March 21, 1617 in the parish of Saint George's, Gravesend. The site of her grave is unknown, but her memory is honored in Gravesend with a life-size bronze statue at St. George's Church.