"The next day her sister drove her to her best friend's house, they said she was fine ... as the day went on she was highly agitated and they told her to go home and get some sleep.
"They last saw her at 6:58pm at Banksia station heading south. No CCTV confirms her getting off a train."
There have been unconfirmed reports of a citing of someone fitting Cassie’s description sleeping on the 5:37am train from Blacktown to Emu Plains with a pink blanket.
"Police have conducted extensive inquiries to date to try to locate Cassie, but at this time have been unsuccessful," read a statement from NSW Police.
"Cassie is described as being of caucasian appearance, about 175cm tall with a thin build and dark brown hair. She was last seen wearing a multicoloured shirt, grey tights and white and gold Adidas sneakers."
NSW Police said there are concerns for her welfare due to her young age and urge anyone with information to contact CrimeStoppers on 1800 333 000.