Check the rules and consider consulting with a real estate attorney.
Usually, the rules in active adult communities state that one purchaser must be at least 55 years of age. If a younger person (over the age of 19) also wishes to be part of that purchase and to live on the premises, the 55+ person is supposed be in residence whenever that younger person stays in the condo. (Hey, you never know what these youngsters--that is, any adult under 55--will do if left unsupervised in a condo).
Marc Jablon, The Jablon Team
RE/MAX Complete Solutions