What about this approach ...
Hey this is Crazyquilter, and I now just how important Masterpiece is to you so I am just confirming that the floral backing is the one you chose for this quilt and you want XXX quilting.
Then let her guide the conversation.
This way you know that the floral blacking was indeed her choice and if there is a problem it can be fixed. Plus it is just one more opportunity to confirm you will provide the services she wants.