"Pythagoras Married Theano, one of his disciples. They brought two children to life, who later continued the mission of their father. "

Taken from: http://www.el-koussa.zgharta.com/el-koussa/books/pythagoras.htm

You can find the same information on other sites such as:
http://www.mathopenref.com/pythagoras.html
http://www.lisashea.com/lisabase/philosophy/art21088.html

Sometimes is said he had seven children, or that Theano was 'a local girl' etc.

Well i was on a website that said Theano was one of his students and not his wife and had no kids

i found that on: http://www.mathopenref.com/pythagoras.html