Asking for names and birth dates of minors on lease

[Daniel Pearson]

Hi all! 

My wife and I have an ADU in our basement and we're getting ready to get our third family in there as our current tenants are moving soon. We're wondering if there's any law that would prohibit us from requesting (not requiring) the birthdates and names of children that will be coming with the new tenants? I know the fair housing laws state that we can't require documents of minors. The reason we're asking is we would like to be able to get them little gifts on their birthdays.

Thanks!