Well, this might answer your question about children. http://www.orlando-guide.info/forums/topic_17175.asp

With regard to a business you can either be partners in the business together or the business can be in one person's name only with the other person on a dependant's visa. In order for the dependant visa person to be able to work, you'd need to apply for permission to do this which takes, I understand, around six months. And yes, therefore the business must be able to support the whole family.