She has a few pieces of Rosenthal china:
That is a teacup and the mark on the bottom of the creamer pitcher.
She wants to know info like - when were they made? Where were they sold? Are they rare or common? Really anything. She emailed rosenthalusa-shop.com but the email bounced back, so that wasn't any help.
It's a long shot I know, but I figured it couldn't hurt to try here. :)