SA, why u are arguing? she said she think its a shameful act, she is not a believer, that you are explaining to her, its up to her best knowledge, 

now the one who know the real story, and why it is like this, he don't feel this a shameful act at all. everyone have his/her opinion, you can never change it by force.

so leave her on her own, if she don't want to understand,