There is no limit, as long as the person can pass qualifying conditions.
3
2010 was her first time at the Olympics.
20
There are 21 at the time.
a long time
this is the 3rd time.
It varied over time.
name 1 person from the Olympics who does gymnastics
Usain Bolt is the fastest man to ever enter the Olympics breaking all records with a winning time of 19.59 seconds.
The 2012 Games in London will Holly's first time competing at the Olympics.
yes
The Olympics are an athletic event, not a religious event. Any person who has a sufficiently good athletic ability can compete in the Olympics, no matter what religious belief that person may have. Olympic competitors are sponsored by their nation of origin, so nationality does get involved, but religion does not.