I looked this up on Wiki.
Between 1956 and 1972 the Nationality Act allowed Birthright citizenship. So it is just about possible that they are Thais simply by being born here, regardless of their parents citizenship.
Look at the section "Jus Soli" here ... https://en.wikipedia.org/wiki/Thai_nationality_law
My wife and I got the document from Banglamung Amphur office when we took our granddaughter to UK for a holiday. The mother needed to attend with us.
Edit to add that this was about 5-6 years ago, but I don't expect anything has changed.
Talley's brand frozen peas are pretty good. Come from NZ and sold inTesco, BigC, Tops, etc.
Simmering for 5 minutes seems a bit long.
I drop them into boiling water, bring back to the boil and simmer 1 minute.