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.
Seven international players are set to play their final international rugby matches as they line up for the Barbarians against the Springbok Women on Saturday 7 September at the DHL Stadium.
Barbarian FC and South Africa Rugby Union announced last week that they will face each other for a third time this September.
The Black Ferns Sevens have claimed gold at the World Series Sevens in Hamilton after crushing the USA.