@Sharon **************
, enter Thailand on a visa-exempt or tourist visa. Definitely TR for a spouse. Depends on how fast you can settle and sort all requirements for an initial in-country visa.
an in-country application would take like this:
1. Apply for an in-country visa at the local immigration office when you still have
*****
days in your current stamp
2. wait for
*****
days (depending on the office) for under-consideration, then go back to IO to get a 90 days stamp on the initial in-country visa for the primary person
3. wait primary person has LESS than
*****
days with the first 90 days stamp, apply for a 1-year extension based on retirement
4. when the primary person gets on 1-year extension, the spouse goes to a nearby consulate to apply for a single entry Non-O dependent visa
5. enter back to Thailand, when a spouse has LESS than
*****
days, apply for a 1-year extension based on the trailing spouse to get a matching period to the primary person
Spouse has to wait until step 4 being on tourist status