St Joseph's Convent School at Iona opened one hundred years ago, on April 11 1915. A report two weeks later said that three Sisters of St Joseph on the teaching staff and sixty children attend daily,
Bunyip Free Press April 15, 1915
The opening of the Convent in 1915, from 100 years of a Catholic Faith Community: St Joseph's Iona 1905-2005 by Damian Smith.
A more detailed report, some of which is reproduced here,was in The Advocate, of April 17, 1915. the full article can be read here - http://nla.gov.au/nla.news-page17855840
Here's some description of the building, from the same Advocate article.
Here's more description of the new Iona Convent from The Advocate, of April 17 1915.