The first thing you'll need to do before selecting a tree, if you haven't already, is to get a soil test. Trees can be an expensive investment and some are very particular about the soil type on the site, moisture levels, and pH. There are also many USDA hardiness zones in Michigan, so you will want to select a tree that's appropriate for your hardiness zone. Most trees will get larger than 12ft. Shrubs may be more ideal in your situation. Here are some potential options: Redbud, Serviceberry, and Buttonbush. Keep in mind that some varieties and species may grow larger than the 12 ft you are looking for.

Here are some other options, depending on your soil type and location.
https://www.canr.msu.edu/news/native_plants_for_michigan_landscapes_shrubs

https://www.canr.msu.edu/uploads/files/Trees_and_shrubs7-13RS.pdf

Homesoiltest.msu.edu