Covid insurance for return to Thailand

Yes.  She needs Covid insurance from date of entry until her current extension expires.

BerryMyers is correct,and it has nothing to do with the airline. The airline will probably only ask for the PCR-test result.

Reading 2 other asnwers, I would not be so categoric...!!

I renewed my retirement visa locally last year in August, bought an health insurance beforehand, but the document was not asked by immigration and even put apart and they told me they did not need it.

Honestly, I would not buy one (expect 1,000 US $  or so !) and would see what happens at immigration when arriving.
Honestly, I think nothing will be asked at all. Passport with retirement visa and re-entry visa will be quite enough, I guess.

if you want to be 200% sure, just contact immigration directly.

pfaure wrote:

Reading 2 other asnwers, I would not be so categoric...!!

I renewed my retirement visa locally last year in August, bought an health insurance beforehand, but the document was not asked by immigration and even put apart and they told me they did not need it.

Honestly, I would not buy one (expect 1,000 US $  or so !) and would see what happens at immigration when arriving.
Honestly, I think nothing will be asked at all. Passport with retirement visa and re-entry visa will be quite enough, I guess.

if you want to be 200% sure, just contact immigration directly.

It seems to me you're confusing the mandatory health insurance/covid-19 insurance you need to be able to enter Thai soil (coverage $20,000 at the moment for foreigners), with the mandatory health insurance for initial O-A and O-X visa holders when extending the stay at the local immigration office. The reason you didn't need one is that your initial visa was a Non-immigrant O which doesn't require an insurance.
The topic is about insurance needed when returning to Thailand, not when extending the stay 1 year at the local immigration office. Immigration has nothing to do with the insurance needed when applying for the Test & Go or a Sandbox somewhere in Thailand.

LEEDS FOREVER  ,    good  reply , good job ,  Very Knowledgeable

Thanks for precisions and highlights