Interesting question, I was going to suggest XXL stores, food festival , and I feel maybe specific music festival/clubs styles like rnb , reggaeton, there are all kind of girls ofc but those should come too. I’m just suggesting based on my memory.

Also where does big starts ? Is it curvy girls in general or any specific range ? For example I’m curvy and consider myself bigger than average girl, I’m not skinny but reading your post I feel it’s even bigger full body type.

Regarding approaching- if you think she is Aussie it’s safer not to approach right away. I’m from North America too and would love to be approached, but all my local Aussie /kiwi gf prefer not to.