A Royal Christmas (2014) on Netflix

Plot summary

Emily Taylor is a seamstress in her family's business in Philadelphia. Her boyfriend, Leo James, has kept a secret: he is Prince Leopold, heir to Cordinia, a small sovereign country. As Christmas approaches he takes her there to meet his mother, Isadora, the queen, who disapproves of the American visitor on sight and would rather he marry Natasha, the Duchess of Warren. Emily settles in with the castle's butlers and housemaids more easily than with the royal family and its guests. While she and Leopold are in town choosing Christmas trees, she makes friends with Poppy, a little orphan girl. The head butler, Victor, coaches her in etiquette, and the queen arranges for the duchess to spend Christmas at the castle.