Simplify the following text for a Grade 10 native English-speaking person.
Original: She often sang with Elisabeth Schwarzkopf , who said in interview that Seefried was naturally able to do effortlessly what other singers , including herself , worked all their lives to do .
Simplified: She often sang with Elisabeth Schwarzkopf , who said in an interview that Seefried could do easily some things which other singers struggled all their lives to do .