The 22-year-old earned her call-up to the South African senior women's team following the national championships earlier this month.
"It was definitely a surprise as I've been out of the game competitively for about a year," said Christian, who also captains the NMMU side.
"Although I have made the national team in the past, it is always such an honour representing my country. I couldn't be prouder or happier."
The Eastern Province defender has participated around the globe in two junior and three senior world championships as well as a tri-nations tournament.
She has also managed the SA U18 team in Australia.
Although this year marked her eighth participation in the senior nationals, Christian said she was always humbled by the opportunity to make her family and supporters proud.
"It's also daunting now because I know I have had a lot of work to do in a short space of time before the Nations Cup; it's not easy coming back to compete at this level after a year off."
The second-year Human Movement Sciences student said Dublin was a chance to compete against teams at the highest level.
"It is amazing exposure for South African water polo," said the centre back.
The team will take on top-tier countries like Switzerland, Austria, Denmark, the Czech Republic, Scotland, Wales and Ireland.
Christian said it was difficult being the only EP team member to make the national side.
"Training by myself takes a lot of discipline and motivation so it has been challenging.
"But I have managed to make it work by following fitness routines and having the support of those around me."
After the Nations Cup, she will turn her attentions to the World Cup in Russia later this year. If selected, it will be her fourth consecutive outing at the international competition.
"I haven't missed one yet and although it will take a lot of hard work and training to get there, I am positive that I will be singing the national anthem in green and gold."