Kelter made her debut against France in 2016 and has gone on play in two Rugby World Cups in addition to three Olympic Games with the national sevens team, including their bronze-medal campaign this summer in Paris.
The Australians open their campaign in Wellington against England on Friday night, followed by matches against France and Wales.
Losing two premier tight-head props will have Australia scrambling at scrum time in France.
Northampton have announced the signing of Fiji Test lock Temo Mayanavanua as their replacement next season for the France-bound David Ribbans.
