So far it seems Mary Ann Foster has managed to cross continents unrecorded.
Thanks to some help from Rootschat, I’ve found that at the time of her father’s death in 1898 Mary was living in Cheltenham, a suburb of Melbourne, Victoria. I still believe she was a nurse, but have also discovered she wasn’t trained at the Royal Melbourne Hospital and can still not find her on any list of Australian nurses bound for the Cape.
The next time we know her whereabouts is August 1902 when, presumably because of her impending nuptials, she asked for and received confirmation of her birth record from the Victorian State Statist, Richard Treacey. This shows that she was in South Africa shortly after the conclusion of the Anglo Boer War and, it can be surmised, she hadn’t just arrived if she had got engaged that summer.
So, sometime between 1898 and summer 1902 she crossed the Indian Ocean. There’s a searchable index of passengers leaving Victoria to foreign climes and as far as I can see, she’s not on it. There is a Miss Foster bound for Fremantle and it is possible that she travelled there first (her sister Matilda was married and living in Perth) which is great, but passenger lists for those leaving Western Australia are not so easily found. Update: I found the arrival manifest which has been digitised on the WA archives site, and while the Victoria archive suggests a Miss M Foster left Melbourne on the Wollowra, she’s not listed when it gets to Fremantle. So frustrating.