@engrllagas u can request from her school po a certificate stating english was used as medium of instruction. dapat may year , course, and other personal basic info ng wife mo sa certificate. most schools know what this certificate is..kelangan lg ma prove na she has 'functional english'..or u can opt to pay if ayw mo magbgay ng cert or ayw mo sia ipag english exam. but its too pricey 3600 aud ata for this.
Goodluck and happy new year!
u cn check more details sa DIBP website;
For each of your dependent applicants who are aged 18 years or older at the time of application must provide evidence of Functional English. If the applicant does not have evidence of having Functional English, you will need to provide a statement indicating your intention to pay the second instalment of the visa application charge.
https://www.border.gov.au/Trav/Visa-1/189-/Skilled-Independent-visa-(subclass-189)-document-checklist
https://www.border.gov.au/about/corporate/information/faqs/how-can-i-prove-i-have-functional-english