But Lucy Bell and her "big" little brother George are so close, they are graduating from Lincoln University together next month.
George, 23, has been a professional rugby player for the Crusaders since 2022, and last year made his debut for the All Blacks.
Between games and training, he has been studying commerce, part-time, at Lincoln University.
Meanwhile, Lucy, 27, has been working on her PhD on soil acidity in the Central Otago high country — close to the sheep and beef station in the Shag Valley where they grew up.
She has been working to understand why the soils are so acidic and rich in aluminium, and discovering which legumes grow best there.
"Legumes are really important for our hill country because they provide a source of nitrogen, which is often a key limiting nutrient. It promotes grasslands."
As children, George said he and Lucy were typical siblings.
"When we were little, we definitely had our fair share of conflicts, but when we both moved up to Christchurch away from our family to study, we kind of bonded.
"I went around to her flat for dinner a lot of times and she always cooked me a good meal.
"I guess it’s always nice to see a familiar face in a foreign place, and that’s how we came to appreciate each other."
George said he was getting close to finishing his degree last year, so Lucy encouraged him to take some summer school papers earlier this year so he would be finished in time to graduate with her.
Lucy said she was so busy encouraging George to finish in time she nearly lost sight of their goal.
"For a second, it looked like I wasn’t going to be able to graduate in time with my thesis.
"I thought, ‘Oh God, I’ve been on George’s case; now I’m going to be the one letting the team down’."
With each other’s support, they got there in the end.
But then they came across another hurdle.
Being a commerce student, George was supposed to graduate in the May 9 morning ceremony; and Lucy, as an agriculture and life sciences student, was supposed to graduate in the afternoon.
So they asked the university if there was any possibility they could graduate in the same ceremony.
And to their surprise, Lincoln made an exception and changed the long-standing graduation format.
The duo were "stoked".
"I’m so grateful Lincoln is allowing us to graduate together," Lucy said.
They are now looking forward to crossing the stage together, in front of proud friends and family.
After graduating, George plans to continue his studies while playing rugby.
He wants to complete a property valuation degree so he can forge a career in that field.
And Lucy plans to take her long-awaited OE in Europe, before returning to New Zealand to find a job in the agriculture industry.
Ironically, it would be the first time she would spend a lengthy time away from George, she said.
"I think as you get older, you realise just how lucky you are to have your siblings.
"Possibly, you take them for granted when you’re younger."
