i think the good part is you can talk about it. We all have our comfort levels and there is nothing wrong with her feeling uncomfortable, she has a lifetime of societal conventions to overcome and for me if someone feels uncomfortable with something they should not be argued with but if she understands why she feels that way a little more she may as you say evolve and change her view in time. i really think you are so lucky to have someone to talk to and that you are so comfortable going out shopping. i still do most all my shopping online.
Have fun and be happy, hugs and kisses,