Joanne took the female class at the show, taking her tally of Aachen wins to six. She partnered WH Bentley, lunged by her father John Eccles.
Joanne also came second with her sister — Hannah — in the pas de deux.
The pair, alongside English senior female champion Lucy Phillips, are now preparing for WEG (2-5 September).
Chef d’equipe Lucy Bell told H&H: “It was a great performance and a good final run before WEG as all her closest rivals were present.”
The girls will all be competing as individuals, as GBR is not sending a squad.
“Unfortunately no squad achieved the scores required in the 2014 British Equestrian Vaulting selection criteria for senior championship,” added Ms Bell.