Yeah, she mixed up the process. She would first need to pay 1900THB for the standard 30-day extension. THEN she could next pay another 1900THB and apply for the 60-day covid extension before 24-May. In total, if all goes successfully, she would have 120 days in Thailand:
Some of us agree, some of us don't. But we're glad to provide you with some amusement. After all, life would be drudgery without finding some amusement in it, no? :p
I missed the part where you were actually applying for a 60-day tourist visa at the consulate in Phnom Penh. In that case, your onward ticket can be for 60 days after your arrival to Thailand. ;)
Good to have both. Also, no need to dump all that onto the desk when you walk up. Only show it if asked to. You may not even be asked for it. But if they do ask, you'll be ready.
Your first night is non-refundable. It's a mandatory hotel booking for the PCR test requirement. I'm talking about the next few nights after that. Book with a credit card with a major chain. They usually have a cancellation policy with full-rate rooms that can be cancelled easily. Double-check.
Onward ticket 30 days from your arrival is what's needed. Once you're in, then you can think about next steps(change your ticket, etc.). You can definitely get the one-time 30-day extension for 1900THB...but FIRST you must succeed in entering as a tourist.
1) Have $600 cash in your wallet before leaving Cambodia
2) When asked why you're back to Thailand, keep it simple. I want to travel and see more of Thailand now since the pandemic finished. DO NOT under any circumstances offer information that you have a condo and belongings still in the country, yada-yada. They don't know that, and they don't care. It does not help you in any way, so don't mention it.
3) Have a fully-cancellable hotel pre-booked for a few days after your "PCR Test Hotel". This shows you are indeed in "tourist mode". Cancel it after you get into the country.
4) Have an onward "throwaway" ticket showing you plan to move on in 30 days.
Dress nice. Be respectful. If screamed at, don't scream back. Don't argue, and just answer the questions with a smile and as few unnecessary details as possible.
None of this guarantees you will pass muster. But also...none of this hurts your chances either. Good luck! ;)