There's the additional benefits of the agents shielding you from Fair Housing liabilities where the tenants can accuse landlords of discriminating and declining their tenancy due to unfair housing practices.

Take a day after you have your friendly conversation and then ask, don't accuse. 

They will not hesitate to lock hosts out of your account based on accusations that the will not even share with you, and take a very long time to investigate.

I know there's a fine line between making unproven accusations and pointing out inconsistencies that may in the end put her on guard and hopefully prevent future incidents like this. 

It's best not to accuse the kids first.

There is a laundry list of criminal accusations against this person and in 2010 one these claims is 'substantiated'. 

Treat everyone the same and that way you can't be accused of discriminating against anyone. 

I am not accusing you of any bias, but I have concerns that this could affect my property value."

I would not accuse the sellers without eyewitness proof.

And to answer one of your other questions, during the last financial crises, lenders were accused of and proven to be, foreclosing on wrong people, wrong property and wrong mortgages.