That should satisfy immigration as you can show 12 months of transfers.
As usual some offices have their own take on things.
For first extension without embassy letter for income method they seem to have their own rules.
The extension stamp would have two dates on it.
One is the date the stamp was issued and another the date "admitted till".
Your 90 days would start from the date issued.
As you used an agent where did agent obtain your stamps.
Funds in bank account 800k+ for TWO months prior to application and maintained for 3 months after application and at other times not less than 400k.
Assuming this is not your first extension the immigration officer will check your bank account back to previous extension.
Will look for 800k maintained for 3 mo ths from date of last application then not below 400k and back up to 800k two months prior to day you apply for extension
Which immigration office are you dealing with?
That attachment you posted is incorrect, however i believe there are one or two "middle ages" immigration offices still believe that it's 3 months prior.
OP, if you are living in Thailand and your current extension is ending you could consider exit Thailand reenter visa exempt and start over with a non O based on retirement.
The non O and subsequent extensions do not require insurance.
Good.
I have answers to some of your questions.
Bumping this now so you can obtain first hand answers from those that deal with extensions based on marriage at CW.
The dual passports can be useful for extended stay in Thailand as with Thai pp entry the normal requirements for tourists would not apply.
However in your daughters case it's a quick visit and the visa exempt using Oz pp has her covered.
After Oct 1 visa exempt entry is 45 days.
Entry by air or land border.
Forget the tourist visa.
Each entry can obtain a 30 day extension.
So eg ...enter by air visa exempt 45 days.
Do one border bounce reenter visa exempt 45 days.
Obtain one 30 day extension to either entry.
All up 120 days.
More if you want.
Edit: just reread your OP. You are only looking for 90 days.
Two visa exempt will cover that.
My post was clear.
Not many folk use and agent for extension and straight away start to meet the financials for the next extension.
Either by transfers or money in the bank.
Hence in vast majority of cases folk having used an agent will exit and reenter to start over.
As you would know overstay 500baht per day and not something you want to rack if wanting elite visa in the future.
In the main I suggested overstay as I do not know what happens if you cannot leave with the get out of dodge 7 days
Not sure if it's a simple overstay after the 7 days.
Remember the 7 days is not an extension.
Expert can advise.
Extensive history and fly out back in visa exempt.....not something I would be relaxed about.
IMO obtain a tourist visa or border bounce.
Obviously the second option best idea when visa exempt goes to 45 days.
Krabi does not have the most simple border run options.
Ok....not an option.
I really hope the pp comes through within the 7 days.
Another option I very rarely suggest is to go onto overstay and pay fine on departure.
If you know the new pp is coming within 7 days then agree with your plan of obtaining the 7 day get out of dodge stamp.
Any permission of stay can be protected by purchase of reentry permit.
Multiple 3800 and single 1000.
By all means obtain your non O-A.
The non O with extentions and reentry permits achieves same result.
Please report back what the cost of non O-A insurance is.
Most folk that use an agent do not start transfers or place funds in bank for extension in 12 month time.
To switch to doing it yourself he would need start over.
New non O
Because they choose not to.
Believe it or not many folk here are not short of funds and opportunity cost on a miserable 800k in a Thai bank account means very little.