Don't change it - and it's okay for others who were there to add their version.
Make opportunites for the student to hear non-Aboriginal speakers.
Look at the teacher here, not the student, the teacher needs advice and follow-up.
Caution the teacher about making judgements of SAE skills on the basis of this text: the student may be choosing to speak in AE, and may speak or write quite differently in a task where he/she explicitly aims to produce SAE.
Use the text to help the teacher recognise and learn about Aboriginal English. This is this student's home talk.