Some information on Amalia and Ferdinand's relationship and travels in 1771:
In the spring of 1771, the sovereigns went on a trip to Castelnuova de'Terzi, hosted by Duke Frederick Sforza Fogliana. After a few days, the duke and duchess proceeded to Salso, next to Scipione, then back to Sforza-Fogliano's estate, where they had the excitement of hunting with hounds, with the Duchess killing a hare. Afterwhich, they went to Firenzuola, where the bishop welcomed them and said mass. Another stay at Castelnuova afterwhich the sovereigns went back to Parma, very contented with their trip.
In July 1771, the Marquis Durfort (France's representative) and Don Pedro Zevallos (spelling? representative of Spain) had a secret meeting with Duke Ferdinand regarding Du Tillot, in which Amalia also joined. The two envoys were there to make a thorough review of Du Tillot's service as believed by the Infante but as later events would unfold, not so -- but to defend and protect the minister. The Infante highly protested the continued service of Du Tillot, saying he would no longer suffer such a minister whose ambition was to dominate, who was greedy, and who had the audacious temerity to degrade his character and that of his wife's, among other things. Amalia also presented her list of grievances against Du Tillot and made several suggestions to remedy their situation. But the two envoys opposed the suggestions, saying that such cannot be made without the 'clearance' of the courts of France and Spain. The excuses made by the two envoys were only pretexts to gain time and save Du Tillot.
(My own loose translation from the book Ristretto di Storia Patria ad Uso de'Piacentini, Volume 5 by Antonio Domenico Rossi)
BTW, on Amalia and Ferdinand's eldest child Caroline, her godparents were Charles III of Spain and Empress Maria Theresa. The travel to Mantua in October 1771 by the duke and the duchess mentioned in reply # 510 was to meet and offer their congratulations to Princess Maria Beatrice d'Este, who was to marry Archduke Ferdinand that month in Milan (both information from same source as above).