Well...I have never seen the "formal" rule about
อุภโตสุชาติ but I understand that อุภโตสุชาติ means "Chao" by "BLOOD" + "Rank of Queen" krub not by rank only
Princess Suvadhana wasn't "Chao" by blood, so Princess Bejaratana isn't อุภโตสุชาติ (same case as King Bhumibol, Princess Galyani...etc.)
In case of Queen Sirikit, she was Mom-Raj-Wong before + the first rank of Queen, so her children are อุภโตสุชาติ krub. (same case as all children of Queen Sunandha, Sawang, Sovabha, Sukumal)
King + Queen who has the royal blood = อุภโตสุชาติ Children.
Anyway, when I go back to Thailand this December, I would seek more information about this, and let you know.
29 พ.ย. 45 08:54:12