[shanice]

Traditionally, Thai of my generation and that of my wife, do not celebrate birthdays in the Western sense. We were present when our niece celebrated her 20th birthday and it came as a surprise to my wife, having not lived in Thailand for over 30-years. Our niece brought a small cake, cookies and soft-drink. She served the cake and cookies to all of the adults present, starting with her grandmother, then her parents and then us, her oldest aunt and uncle present and then the others. She gave grandmother a small gift and her mother one. We all sang "Happy Birthday", in English, and that was that. We gave her a card and it contained a small amount of money and she was taken aback and did not know how to respond to it. She sought permission to accept it from grandmother.
I guess it all depends upon the family and the circumstance and the environment in which they were raised and what influence the West had on their upbringing. I know that my wife said while growing up she and her family did not celebrate their birthdays other than going to the wat for merit-making.