@Joseph **********
they can't be sending teachers to Lao because the country isn't open to individuals, you can't walk in or fly in unless it's as James outlined. 😕
Cambodia is where people are getting their Non-B visas right now, not Lao
As people pointed out it's gonna come down to the company issuing the documentation AND the immigration office you're dealing with as far as if you can go from being a dependent (which I think you mean trailing spouse).
Now as far as I know a "trailing spouse" extension can't be switched to ANYTHING ELSE inside the country, and other than a covid extension, when you lose your extension she loses hers automatically.
You need to be talking to the immigration office and the company that she's gonna work for to see what they say but my guess is no it can't be done without leaving and comin' back on visa exempt or tourist visa entries to start the in country Non-B process (IF that office issues them)