How can my niece on F1 get instate tuition of state I'm a resident of

My sister-in-law is coming to live with my wife and I while she attends a private english school in order to take the TOEFFLE. She will be on an F-1 visa. Is there a way to use our residency in Nevada when she passes the TOEFFLE and starts college at a Nevada state school? She is currently 17, but by the time she starts at a state school she will be 18. I am a US citizen and my wife has her green card, about to apply for citizenship.