Here is some hotel info from my friend (actually friend's mom)
Edison Inn - Right on the river under the bridge. $115 river view, $100 partial view, $90 neighborhood view - 810-984-8000
Best Western - Water Street, $70-80 810-987-1600 $70-$80
Fairfield by Marriott - Yarger Street (right off expressway into town) $109-$149 810-982-8500
Hampton - right by Fairfield $129 but they are full 7/24 if that is the day, 810-966-9000
Quality Inn - Hancock, at the end of I-69, $109 810-987-5999
The Best Western, Fairfield, and Hampton are all in the same area, not to far from the Seaway. Maybe 15 min. if traffic is good.
If she can get a room at Edison Inn for $115 that is the best place. Great view and better than any of the other hotels listed.
Re: Greenglam