and at the embassy/consulate at home you just use your income or funds at home to qualify. You open a bank account in Thailand and bank the required 800K baht within a month and apply for your first year extension of stay after two months.
You’ll need to go and ask them and ask for a 7 days extension denied stamp on your current exemption/extension in the first place and maybe do a border bounce. But they have to advise you, 15-21 days should normally be sufficient for a Non O in country.
It’s seven days prior to the application for extension of stay based on custodian of a thai child.
EDIT
7 days requirement was from one immigration. At the immigration in Bangkok it’s sufficient with the funds in your bank account at date when you apply. I suggest you ask your immigration, but there’s no two months seasoning requirement as for marriage.