However, like many siblings, Becky and Elly have grown closer as they've gotten older and always work out their differences.
"We do fight, sometimes you just fight about small things but Elly and I have a really beautiful relationship where we're really respectful of each other and we love each other at the end of the day," Becky shared.
"No one's perfect at the end of the day so as long as you can admit you were being a bit silly and apologise I think that's all that matters. It's all about respect."
The bond between the Miles sisters is certainly a strong one, as evidenced in the sweet post Elly shared to mark Becky's birthday - which is also International Women's Day.
"The fact that today is also International Women’s Day is quite fitting because you are one of the most influential women in my life and I look up to you immensely," Elly wrote back in March alongside several photos of herself and Becky over the years.
"You have always been so kind, considerate, loving and caring to those around you. You are always exuding good vibes and just want everybody to be happy. I know for a fact that I wouldn’t be the person I am today without you sis. I am extremely proud of you and proud to be your sister. I have so many cherished memories with you and I look forward to creating more! Happy Birthday you incredible woman. Have the best day ever!!"
Though Becky and Elly are no longer with their respective Bachelorette winners Pete Mann and Frazer Neate, the eldest Miles sister is no longer single.
Shortly after Valentine's Day, Becky revealed that she was dating fellow Newcastle local, James Bevitron in a heartfelt Instagram post.
“Yesterday I took this pic and thought it was hella cute...This is what a happy Becky looks like and it feels pretty damn good,” she penned in the caption.
“I feel understood, appreciated and loved by you and that’s a pretty amazing place to be...Here’s to many more kombi #vanlife adventures with you.”