@Pa**
, extensions of stays at the immigration office based on marriage or raising children are issued for a year at a time (so you wouldn't leave every 90 days, that's only for a visa you get outside of thailand at a consulate). You just do 90 day reporting at the immigration office
What I was saying is; if you are using th 400K baht banked money for the financial requirements for a yearly extension based on raising children at the immigration office there is no requirement the money is seasoned at all. Unlike marriage extensions that require 2 months of seasoning.