The dates are important. As BinSabai notes, if you dont fly 50k in either the first or second 12 month perid of the 2 year validity, then you must fly 80k itotal in the 2 year period.
Her ROP Gold is valid for two years. From the information you provided it isnt 100% clear if she gained TG*G on 22/12/17 meaning her 2-year period will expire 22/12/19 (case A); or if her 2 year period will expire on 22/12/18 meaning she qualified on 22/12/16 (case B). You seem to be asking about case B.
For case B, your friend can only requalify by flying 5000 miles before 22/12/18. Flights in Jan 2019 won’t matter, except for trying to get back to gold from silver.
A biz return flight Bangkok to Bali would just about do it, or 5 domestic return flights - but these need to be done by 22/12.
For case A, either as above to meet the 50k requirements in 1 year, or fly 35k miles from now until 22/12/19 to meet the 80k requirement in 2 years.
Last edited by Thai-Kiwi; Dec 1, 2018 at 12:00 pm
Reason: correct iPad errors