Cooney-Cross had been due to play for European champions Arsenal in the Women's Super League against Manchester United on Saturday as the English competition resumed after its Christmas break.
But the 23-year-old has revealed in an emotional social media post that she's raced back home to be with her mother Jess.
View this post on Instagram A post shared by Kyra Cooney-Cross (@kyracooneyx)
Sharing a photo of the two of them together in hospital, Cooney-Cross explained her mum had been diagnosed with a "rare and aggressive" form of bile duct cancer.
"A few days ago, our world changed forever," she said.
"My amazing mum, Jess, has been diagnosed with stage four cholangiocarcinoma (bile duct cancer).
"It's a rare and aggressive cancer, and there is no cure.
"'My mum is my hero, my best friend, my everything and the person who has shaped every part of who I am.
'She is the reason I am where I am today, her strength, love, and belief in me has carried me through everything.
'Trying to put into words what she means to me feels impossible.
'I'm now back in Australia to be with my mum, my sisters, and our family as we navigate what comes next. We are all still in shock and learning how to sit with the weight of this news."
The midfielder's Arsenal and Australia teammates, including club colleagues Steph Catley and Caitlin Foord and national skipper Sam Kerr, have rallied round Cooney-Cross with messages of love and support.Â
The Matildas official Instagram account posted in the comments: "We're with you every step of the way."
� Introducing our December Player of the Month, as voted for by you...— Arsenal Women (@ArsenalWFC) January 7, 2026� Kyra Cooney-Cross �
Cooney-Cross has been enjoying her best spell with Arsenal since she signed from Swedish side Hammarby in 2023, a fact recognised by her award earlier in the week as the European champions' player of the month.