As I understand it the key thing is to prove that the original currency wasn’t Thai baht. Foreign bank/currency transfer bank -> Bangkok bank > destination bank in Thailand. Show a paper trail reflecting this (including purchase of Thai baht) along with transaction statements. Otherwise it does look like an internal transfer.
I was waiting for you to say that 🙂 Robert.. would she not be better off booking a flight to Laos (within the 30 days) and then getting a proper 60 day tourist visa?