Condo Association Troubles!

My sister is selling her condo, but the woman who live below her is too much. Someone put an offer in about 20 percent lower than asking price. My sister declined. 2 weeks goes by and this same person put in an offer at asking price. Cash. They seemed very interested. They asked to look over the financials of the condo association. When the real estate talked to a member of the association about the records, the woman living below my sister, she said that she wanted to vet the prospective buyers. Real estate agent reminded her that was illegal and she should not engage in any conversations regarding who they are, they're habits, etc. wellllll ....this lady ended up GRILLING the prospective buyer about all sorts of personal things and made the prospective buyer so uncomfortable, they dropped the offer. They informed their real estate agent it was directly based on the woman below my sister's questions.
In Michigan, do we have a case against the condo association or this woman personally? Very upsetting.
[link] [comments]