What are the best visa extension options for my wife visiting Chiang Mai on a Visa on Arrival?

Hello Everyone,

Wish you all a terrific 2019.

I'm a digital nomad from India staying in Chiang Mai(CM) for sometime now. My wife came to visit me on a "VISA on Arrival(VOA)" on 22 December 2018, and got an exit stamp of 5 January 2019 but wishes to stay until 19 January 2019.

I've heard of CM's Visa Extensions and Border Runs and have few options/Qs that I'm contemplating and need your advise on:

Option A: She does a Border Run.

Q1) Would Mae Sai – Tachileik, Myanmar be the most convenient border run? further...Would calling the Myanmar checkpost beforehand at Mae Sai be a good option.

Option B: She does a Visa extension at the CM Immigration office?

Q1) How many days of an extension can she get?

Q2) if She gets a 7 day extension(which is what I've heard for Indians, then can Border Run be chosen thereafter(or will border run be entertained by Thai officials at the Mae Sai border?)

Option C) She catches the flight back to India(Kolkata airport), and comes back to Chiang Mai- the most inconvenient option.

I'd love to hear from your experiences and spread this info into my circle.

Thanks for your reading and help.