Can a green card holder not live in the United States or just stay for a certain amount of time per year?

No, it is not easier to get a green card being a nurse. If you have a Masters degree in Nursing in a specialized field, it is possible you could get a work visa which can eventually lead to a green card if your employer sponsors you. If you only have a Bachelors degree, you will not be getting a work visa.
If you have a green card, your parents cannot get one through you. Green card holders cannot petition for parents.
Your mothers sister can petition for her only, it will take at minimum 10 years until she could move here with a green card. Once your mother gets here, she would have to petition for your father. Citizenship comes after having a green card for 5 years.
When you graduate, you have to return home. Having a student visa does not allow you to stay after your schooling is complete.

A green card holder is required to live in the US


pre 2006 a nurse could go straight to a green card thru a schedule A visa ...
POTUS put a stop to that in 2006 and want home grown nurses only

the student visa is non immigrant you do the course and leave

your mums sister can file for her

each 365 days, hundreds of green card holders stay outdoors the U.S. for greater suitable than 365 days. people who utilized for a reentry enable before they left can use the reentry enable to return to the U.S. A reentry enable is valid for 2 years. people who did no longer persist with for a reentry enable before they left have located themselves interior the risky place of being considered abandonment circumstances. the government takes the region that a green card holder who has been long previous for greater suitable than one 365 days has abandoned his place of abode interior the U.S. till he took steps to maintain it by ability of making use of for a reentry enable. everlasting resident extraterrestrial beings who're no longer able to return to the U. S. in the holiday validity era of the Alien Registration Receipt Card, or the Reentry enable, might persist with to the closest U.S. consular workplace for a definite immigrant Returning Resident (SB-a million) visa. If the Returning Resident (SB-a million) visa is refused pondering the alien has given up his place of abode interior the U. S., it could or won't be achieveable to acquire a nonimmigrant visa, finding on however if the applicant has everyday an area of abode out of the country to which he will return. If the applicant wishing to return to the U. S. can not post convincing info of compelling ties out of the country he might could persist with for an immigrant visa on a similar foundation by ability of which he immigrated initially, if it fairly is achieveable.

Green cards are intended to be used to live primarily in the US, although you can stay out for up to a year without automatically risking it, or 2 years with a re-entry permit. Still, it's not a permanent tourist visa, so if you normally spend most of the year outside of the US, at some point, they'll refuse you entry and take your card away.

In any case, it's likely to take you quite a while to get a green card. as noted, there isn't any nurse program for this anymore . you might still be petitionable depending on the circumstances but that petition might well take 6 years or more itself. talk to your school about this sort of thing and see what they have to say. You have to be a citizen to sponsor your parents for green cards. your aunt certainly could sponsor them, but it will take her petition 11 years before it becomes valid for use. add 5 more years for citizenship.

Green card holders must live in the US.

As a student visa holder, you are required go home when you leave school.

There are no nurse visas. MAYBE if you get a PhD in nursing, get published an known, you can get an H1B, and 12 tears later, IF your employer agrees to sponsor you, you can get a green card

Green card holders may not sponsor their parents.

Your Aunt can sponsor your Mother only. It will take about 10 years to a green card, and a total of 15 years to citizenship.

After your schooling is over you would have to return home. A student visa is not an immigrant visa. You could file for a Green Card but you would need to find an employer is willing to wait the 6 years it takes to get one.