If wife has inherited property in a foreign country, meaning that the property has transferred to her after someone died, and she has kept the title to the property in her own name, separate from her husband, then generally it is considered separate property under Michigan law, if there is a divorce between husband and wife. There are exceptions if the husband has contributed to the acquisition or maintenance of the property.
There is not enough information about husband's property. Is it held in joint names? If yes, then wife has an interest in the equity. If the property belonged to her husband before the marriage and wife's name is not on the title, it would be separate property. Wife would not be entitled to share in that property equity.