Air New Zealand flew the family - husband Michael Bacher and her two children - from Auckland to be with her, the airline confirmed.
In a statement, Air New Zealand said Captain Barbarich was a "well-known and respected long-haul pilot" who had worked for the airline for 27 years, flying both domestically and internationally.
She was in the process of transitioning to Air New Zealand's newest fleet, the Boeing 787-9 Dreamliner, from the 747 fleet, the airline said.
Flight NZ175 from Auckland was a 787 Dreamliner with four pilots on board as part of the training programme, which includes completing a required number of flights on the new plane.
Air New Zealand's chief flight operations and safety officer David Morgan said passengers were not endangered by the medical emergency.
"Ann was at the controls when the aircraft landed in Perth and the aircraft landed normally," he said.
"Unfortunately after landing she became seriously ill. Another pilot took over and taxied the aircraft to the gate while the other pilots began to assist Ann. The aircraft was safe and under control at all times.
"Ann will be sadly missed by everyone at Air New Zealand. We have been actively supporting her family over recent days and will continue to do so. Our thoughts continue to be with them at this difficult time."
A tribute notice described "our Captain Annie" as the "darling wife of Michael and proud mother of Bianca and Alex".
"She has left us far too early, may her spirit fly free till we meet again. Love you always."
Aviation body CTC Aviation also paid tribute to Captain Barbarich, with the organisation's chief operating officer Peter Stockwell saying staff were "shocked to learn of [her] untimely death".
"As one of the earliest women to join Air New Zealand, Ann was well-known and a friend to many of our senior staff," he said.
"She supported CTC Aviation training methods, in particular facilitating overseas aviation specialists as guest speakers to our Hamilton Crew Training Centre, thereby enhancing our knowledge of aviation."
Captain Barbarich was "very well-known" in the industry, and was "a great role model for women in aviation".
"She will be greatly missed from the New Zealand aviation scene. CTC Aviation conveys its sincere condolences to Ann's family, friends and colleagues."
Captain Barbarich will be farewelled at the Holy Trinity Cathedral in Parnell next Friday.
In lieu of flowers, the family appealed for donations to be made to Koru Care.