Holdover tenant/occupant questionnaire

[Account Closed]

I am closing soon on a duplex in St. Paul, MN which I intent to owner-occupy. There is already a month to month tenant in the other unit with 2 people listed on the previous lease. It’s a 2 bedroom unit and there are plenty of toys around so I assume at least one minor also lives there (though I have never seen any of the occupants). I’m going to present the tenants with a new lease and would like to make sure all persons over the age of 18 are on it (and would also like to know how many total people are living there). Is it against Fair Housing laws to ask the current occupants to fill out the names and birthdays of all the people currently living there? Or is there a better and legal way to approach this? Thank you in advance for your input.