If she is from a visa exempt country she may come visit you for 6 months at a time, though she may apply for extensions to this time period and potentially stay the entire length of the application processing period with you. If she is from a nation that requires a visa I would recommend she apply for a visa before you get married, because once you are married it may be hard for her to convince them that she will leave the country once her visa expires. I have seen many people say on here that it is very hard to get a spouse a temporary visa for this reason.