What visa options are available for a New Zealand citizen planning to stay in Thailand for 80 days?

Do the visa exempt 30 + 30 days get train from Hat Yai to Padang Besar or Butterworth and return to Hat Yai.

Apply for a tourist visum 60 days. It is electronic I think and answer is quite fast. She needs a pile of documents like passport, vaccination, tickets and where to stay. But it is not too difficult. You find the page on Thai embassys addresses. You obtain a paper to bring to immigration. No visum stamp in the passport.

When you come you can the prolong 30 more days.

Since you said 80 days is the intention, the wisest course would be to apply for TR60 at a consulate in Europe. On arrival to Thailand she will get 60 days stamp. This stamp can be extended for additional 30 days without exiting Thailand. (1900THB at local immigration office).

Onward ticket just in case , many websites , 7.99usd is cheapest

If she really plans to stay over 60 days she should get a Tourist Visa so we can extend to 90 days.

If she may stay less then 60 she can enter exempt and extend and do a border run if she wants to stay longer than 60 which could get her up to 120 with the extension then and 2 entries.

Hard to say which will be cheaper and easier.

Not sure if her current flex ticket will work if asked or not. May be worth buying an onward ticket if she can’t make it show leaving in less than 30 or 60 depending on how she enters. Google onward ticket for options that are cheaper.

You would need to apply for a tourist which gives you 60 days and then she can extension that by a further 30 days which is a cost of 1900baht however I'm not sure how it works as she is in another country when she applies ?

Someone else might know ?

In addition to above may also be asked to show proof of funds I believe it is 20,000 baht which can be equivalent in other currency

If she enters visa exempt she will be stamped in for 30 days. She can extend this for another 30 days at a local immigration office. That is 60 days total. She would then need to leave and re-enter the country if she wants more days.

She may also need to be able to show travel out of Thailand within 30 days to be able to board her flight to Thailand as she does not have a visa.