* there were actual tariffs imposed when you imported the results of her labor, reflecting the very different costs of living in two nations
* the nation where she works had the same environmental and labor regulations as where you live.
* there were barriers to you directly or indirectly investing capital in the nation where she lives, and/or significant taxes on the profit you make from doing so.
* the nation where she lives had a strong union/pro-labor culture that gave workers the power to collectively negotiate with employers.
* the nation where she lives had a legal system that would reliably hold employers and investors responsible for their decisions.
Now, you might still choose to pay for overseas labor even if all these things were true, but you likely wouldn't be paying $3/hr anymore. As it stands, "cheap overseas labor" is about much more than that.