Can a tourist marry in Australia?

hi, i just want to ask if me and my girlfriend can marry in Australia i am a Filipino Citizen and she is a Canadian Citizen. our problem is she cannot provide her birth certificate. we will only be there as a tourist cause i will be coming from Philippines and she will be coming from Canada, we just want to get married legally. is there any other options we can provide besides from Birth Certificate as a requirement to marry and if so what should we do first ? thank you..