Australia finished in third place at the World Netball Series, having lost just one of seven matches during the modified rules tournament.
The Diamonds were unbeaten going into Sunday's semi-final against England but struggled to penetrate the home side's experienced defence and lost 27-17.
"We couldn't stop some of their key players and we started to not shoot as well and get a bit of pressure at the front," coach Lisa Anderson told AAP.
"Quite a few of our balls were thrown into England defenders' hands.
"Overall it was disappointing. It wasn't a performance worthy of how we have been playing."
While England went on to win the series, beating New Zealand 33-26 in the final, the Diamonds claimed third place with a 32-24 victory over Jamaica.
Played over three days, the tournament's modified rules include six-minute quarters, one of which is selected as a "power play" where goal points are doubled, and unlimited rolling substitutions.
Australia sent a selection of emerging players to the competition and Anderson said the loss to England will teach an important lesson.
"They were bitterly disappointed after the loss but came back for the consolation final and put in a great match," she said.
"All the girls can be really proud of how they have played over the three days."
Alexander said the series is "extremely valuable" not only for players, but for coaching staff.
"I can't say how much it really assisted me to see which players can really step up to the height of the competition and who can really take their game to a whole new level," she said.
The Diamonds return to Australia on Monday for a short break before starting pre-season training with their ANZ Championship teams in January.