Extension of the E3 visa to the travel visa

My friend is in the country with an E3 work visa that ends in April. She plans to return to Australia when the E3 visa is over, but she has to stay here to see the Rolling Stones in May! So my question is: can she just apply for a travel visa when she's already in the country and stay longer without having to go back to Australia? And how would she take it to extend her stay for a month or two? She will not work anymore after the end of the E3