Actually, quite a few of the schools I applied to asked about any alumni relatives. I don't think that your chances necessarily fall if you say no, but I think it is a slight benefit to be related to someone.... if that made sense.
This is an excerpt from an email I got from them:
"After you submit the online supplemental, you will be
directed to a link to pay the $70 application fee by credit card
or e-check using TUPay. Your supplemental will be processed by
our office when we receive the application fee. If you participate in
the AAMC Fee Assistance program, the supplemental
application fee will be automatically waived. We can only grant
supplemental application fee waivers to applicants who participate
in the AAMC FAP."