check the prices on GoodRx, that shows thing cost at supermarket pharmacies and chain drug stores in the US and for genetic (off patent) drugs the prices are usually lower than the prices at independent pharmacies in Thailand.
those probably sell for pennies in the US too. Prices that I see on GoodRx have always been a lot lower than here on the drugs that I've needed. I've encountered some spectacular examples firsthand, such as Temozolomide pills (a chemo drug) costing roughly $3000 per month at Chiang Mai Ram Hospital versus $600 at Northside Hospital in Atlanta.
those are still not dirt cheap. If we focus just on generics, every drug that I've ever been prescribed that is available as a generic cost a lot more here, at a Thai pharmacy, than what it would have cost at a Publix supermarket pharmacy in the US.
maybe for drugs that are still on patent but generic meds located though apps like GoodRx in the US are almost always cheaper than at Thai pharmacies, often by a lot.
I'd still put together a will to make sure that her right to the money (and any other assets you mightvhave in Thsiland at the time if your passibg) is unambiguous. I don't think that my wife would remain calm and well enough composed to immediately start draining bank accounts when she learned of my passing, so having some means of the money eventually getting to her on its own would be key.