Irwin, who turned 15 on July 24, spent the day at Queensland's Australia Zoo (where she lives with mom Terri and brother Robert, 9½) feeding crocodiles and cuddling koalas. The teen – daughter of the late "Crocodile Hunter" Steve Irwin – even received a zoo-shaped cake to mark her special day.
"So excited to be 15 today. I'm feeling blessed to be spending my birthday with my wonderful friends and family @AustraliaZoo," Irwin Tweeted, thanking fans for their wishes in a second message.
Irwin recently began an acting career, starring in 2013's TV movie Return to Nim's Island, and told PEOPLE last year that she hopes more roles come her way. But her first love is still carrying out her father's messages of animal care and conservation.
For now, though, the 15-year-old is likely relishing in the memories of her big zoo bash. We can't wait to see what her Sweet 16 celebration will be like!