(Florida resident acquired home used as primary residence as joint tenant with right of survivorship with his mother, and at time of acquisition had minor child; state constitution provides that the "homestead shall not be subject to devise if the owner is survived by spouse or minor child"; resident died and court held that residence was not decedent's homestead with result that it passed at decedent's death to mother as surviving joint tenant; residence not homestead property at time of purchase, thus constitutional provision inapplicable).