A 1997 animated series that is very loosely based on the younger years of Elisabeth of Bavaria. AKA Sissi (Princess Sissi)
More specifically, the story focuses on the plucky young farm girl nicknamed Sissi who falls in love with Prince Franz from Austria. The rest of the series tells of the trials and troubles it takes for the two of them to actually get married. There's her future mother-in-law, who's looking for a better girl to marry her son; political tensions, Sissi's own father, and lots of danger and wacky adventures in between.
However in real life their lives were not such fairly tales. Sissi married Franz at 16, while he was 24. Helene was acturaly her older sister who was 18 at the time.