Of course I'm not familiar with your situation, but I have found that the more mrs non-fixie became aware of what vintage bikes are all about, the more she softened up to me buying them. What really made a difference was taking her along to C&V events (L'Eroica and Retroronde). She really liked those, albeit for slightly different reasons than I. She decided she wants to ride both with me this year. I'm OK with that.