Use nth-child, for example: http://www.w3schools.com/cssref/sel_nth-child.asp
driver.find_element(By.CSS_SELECTOR, 'p.content:nth-child(1)')
or http://www.w3schools.com/cssref/sel_firstchild.asp
driver.find_element(By.CSS_SELECTOR, 'p.content:first-child')