Not 100% on this, but from talking to someone that was a year ahead of me, I would say...
'fraid not. I think that her only choice would have been to marry someone from Michigan and then
maybe she could have gotten in-state tuition.
I would suggest that you contact the folks in financial aid (at least one of them is really good) and run that question past them.
BTW I don't think that it's a WSU thing, but rather a state of Michigan thing that if you start off as an OOS student then that is the rate you have to pay all the way through. Also think that it takes more than just owning some property to declare residency - that information could probably be found on the state website (
www.michigan.gov).
But for anyone that wants to try that route, my place will be up for sale this summer.