SuperJan took the words right out of my mouth.
You might also show her pictures of quilts that are white and cream so she can see how beautiful they are. I know Alex Anderson wrote a whole book about neutral quilts and they are gorgeous.
There are quite a few to be seen here also:
https://www.pinterest.com/search/pin...utral%20quilts
More:
https://www.google.com/search?q=neut...w=1138&bih=548
If she still insists on white-on-white, maybe something here will inspire you:
https://www.google.com/search?q=neutral+quilts&source=lnms&tbm=isch&sa=X&ei=o0RJVZaLGo2xyATUpYCgCA&ved=0CAgQ_AUoAg&biw=1138&bih=548#tbm=isch&q=white+patchwork+quilts