Secundum Orbergensem in hoc capitulo, sic Dido dicit: "In litus eiectum, egentem te excepi et—demens—partem regni dedi, classem amissam restitui, socios a morte servavi!""
"Gratiam sibi referendam putabat quod Troianos servaverat" = "She figured that favour/gratitude/esteem was due[/ought to be given] to her because she had helped the Trojans."
Sed verum ambiguum est quod et hoc habes:
"She figured that a service/favour [given to Aeneas] was due[/ought to be repaid] to her, namely that [/the fact that] she had helped the Trojans." This fits the question "quam gratiam...?" // quod aptum est quaestioni citatae.
I'm writing in Latin hoping for correction, and not because I'm confident in how I express myself. Latinè scribo ut ab omnibus corrigar, non quod confidenter me exprimam.