Who Is “She” in “She’ll Be Right”?

In Australia, “Don’t stress—she’ll be right” means “Don’t worry; things will work out”. It is not about a particular woman. Here, she can stand loosely for the situation or thing at hand. Australian English sometimes uses she where more standard international English would use it.

A: It might rain during the barbecue.
B: She’ll be right. We can move it under the verandah.

The expression is informal, friendly and casually optimistic. It sounds natural in both Australia and New Zealand; with speakers elsewhere, “It’ll be fine” is safer. She’ll be right works well as reassurance about a minor problem, but it can also sound as though a genuine risk is being dismissed. When safety, health or an important decision is involved, explain the solution rather than relying on the phrase alone.

A Chinese speaker who reads the words literally as “the woman will be okay” can miss the context. If she genuinely refers to a woman, that person will normally have been clearly mentioned. Tone matters too: said warmly, the phrase reassures; delivered with a shrug, it may sound more like “don’t bother about it”.

Sources
https://www.abc.net.au/education/learn-english/conversational-australian-phrases/9341170
https://slll.cass.anu.edu.au/centres/andc/meanings-origins/all