my sister would like to know this for some strange and bizzar reasion
It depends on how many people are making them. Depending on skill it takes about 2-5 minutes to make a crane. If you dedicate 5 hours a day that makes 7-50 days if one person is making them. Cranes are often made for memorial. It is a Japanese tradition, especially for Hiroshima. You make 1000 cranes as a memorial for the lost lives. She should definitely get her friends to help.
