What are the visa application differences for my wife as a dependent on my Non O-A visa?

Okay we need to understand the dofference between a 90 day single entry Non-O visa <- which allows ONE entry of 90 days and a year-long, multi-entry Non-O visa which allows unlimited entries of 90 days each time for the year the visa is valid for. When the 90 days runs out she would go to the border, stamp out of thailand, stamp in&out of another country and then stamp back into thailand to get another 90 days.

I would weigh in and say;

IF you are getting a year-long, multi-entry Non-O-A visa from your country before you come here, the logical thing would be your wife to apply for a 90 day single entry Non-O visa. When you both arrive here you'd be stamped in for a year, and your wife would be stamped in for 90 days. When that 90 days runs out your wife would apply for a yearly extension of stay based on being married to someone who is allowed a long term stay in thailand at the immigration office for 1900 baht.

When you apply for the Non Imm. O-A Visa Multi-Entry (age 50 or over) in your home country... Your wife can apply for a single entry non immigrant O Visa 90 Days. Upon entering Thailand at the last 30 days of her 90 days - you and your wife can go to the Thai immigration office near where you are residing and she can apply for a One Year Extension of Stay for a fee of 1900 baht, Application TM.7 Form and other documents. Upon that One Year Extension being granted - you and your wife will then just have to report to the local Immigration office every 90 days.

You need to apply for her for the 1 year Multiple Entry Non Immigrant O Visa. You will get 1 year of stay on each entry, she will get only 90 days on entry.