It depends on what year of the Summer Olympics. In 2012 and 2008, 204 nations participated in the Summer Olympics. In 2004, 201 nations participated in the Summer Olympics.
Jamaica competed at the 2012 Summer Olympics with 50 athletes in 4 sports
Sweden competed at the 2012 Summer Olympics in London with 134 athletes in 20 sports
Softball and baseball were competed at the 2008 Summer Games but will not be competed at the 2012 Summer Games. They will not be replaced so the 2012 Games will have 26 sports where the 2008 Games had 28.
The athlete who competed at the 2012 Summer Olympics, who is also competing at the Paralympics, is Oscar Pistorius of South Africa.
Luke Thomas Michael Hall is a Swazi swimmer who competed at the 2008 Summer Olympics and the 2012 Summer Olympics. He placed fourth in his heat.
olympics london 2012
204 Nations will have at least 2 athletes
No she was not one of the British Weightlifters who competed in the 2012 Olympics