Weir died at the age of 23 after a horse riding accident.
Her family and representatives confirmed her death on Thursday.
The tragic incident occurred on April 2 while Weir rode horseback at Windsor Polo Grounds in her hometown in Australia. She suffered fatal injuries after her horse fell, was immediately taken to Westmead Hospital, and remained on life support for two days before passing away.
The budding social media influencer’s last Instagram posts were quickly inundated with tributes to the young rising star who “lit up every room,” according to one friend, adding, “Heaven has gained the most beautiful angel today. I’ll miss everything about you [Sienna]; I love you.”
According to local media, her boyfriend, Tom Bull, added, “We loved with a love that was more than love.
Weir’s modeling agency, Scoop Management, shared a video tribute with a photo of the equestrian rider smiling, stating, “Forever in our hearts.”
Weir earned a double degree in English and psychology from Sydney University. She shared her plans to move to the UK with local news outlets, aiming to expand her professional and social networks while spending more time with her family.
The horse rider frequently talked about her love for horses that are cuddly and English literature, mainly Gothic poetry. She mentioned that both of these interests distinguished her from the other 26 competitors in the running for the 2022 Miss Universe Australia title.
“Even though I mostly lived in the city, I have a strong and enduring fondness for show jumping,” she stated in an interview with Gold Coast Magazine in September 2022. “My family is not sure where my passion for horse riding comes from, but I have been doing it since I was three years old and cannot imagine my life without it.”
When Aussie’s then-reigning Miss Universe Daria Varlamova asked Weir about her “essential qualities,” she responded, “I must say that I am open to opportunities, sociable, dedicated, multi-faceted, and have integrity.”
Weir, nicknamed “Gremlin” by her friends, said, “It’s important to stand by what you believe and love. You never know what opportunity is around the corner. Trying new things and knowing yourself is vital. I wouldn’t be here if I hadn’t done that.”