Posted to Facebook - page is open if you have FB:
https://www.facebook.com/Peregrine-Falcons-Southeast-Michigan-164682993603101"Update: Whittier Apartments, Detroit : Local volunteer, Thyme Warner was able to identify both Peregrine Falcons today. She saw them mating and had the patience to get photos of the bands. The male is still Fryer (black/blue, 43/C) who hatched in Flint in 2016. The new female is Sandy (black, Y/97) hatched in Ontario at the Toronto Sheraton in 2015. Good job, Thyme!"
Sandy (black, Y/97) hatched in Ontario at the Toronto Sheraton in 2015.

I have to think at her age she's been nesting elsewhere prior to this but not spotted. Great to see her!
P.S. as an aside...Sandy's mother Rhea Mae's sister Ihteram nested in Michigan for a year or so.