I have a sister who is a nurse, who can she come over there in USA for job or to continue her study.?

she studied about lab in nursing {practical} and she wants to study the theory part of it. How can she.

The demand for registered nurses in the U.S. is sky high and the supply is scarce, especially in the case of nursing homes seeking to fill positions. And as our population grows older, the demand in such settings for registered nurses and related health care professionals, such as physical therapists and certified nursing assistants, will only continue to increase.

As far as registered nurses and U.S. immigration law is concerned, it appears that confusion continues to run rampant in communities across the U.S., the Philippines, India and elsewhere regarding exactly what options exist for nurses to travel to the U.S. and work. And the confusion is particularly acute for those families being forced to cough up huge amounts of money in order to facilitate the deal they believe will allow their R.N. family member to travel to the U.S.

I believe she will need sponsorship as per our US Immigration laws - however, with the current need for those in the medical services, you never know, this might be quite easy to do! At least give it a try!
Here is an interesting link that answers questions regarding nurses coming to the States: http://www.usavisacounsel.com/art_34.htm

where are you from?