Send money from your UK bank to her Thai bank via either Wise or Currency Club. Both will offer similar rates. You will have to submit copy of your passport to currency club to register for Anti Money Laundering.
till the Embassy uses IP recognition of the computer in Thailand even though there is evidence of accommodation in the country where the Embassy is. No guarantees here.
you get 180 on entry , to extend you provide ALL your documents originally submitted with timestamped updates. Leave and return its no problem. Even after your extension it’s compulsory leave and return. That’s what you have.