It seems like the average age of female flight attendants has gone up to over 35 in Thai airways and they are now planning to offer voluntary retirement  to flight attendants that are over 45. They will of course offer a generous compensation to the ones that retire but in the end it is all about saving money as senior flight attendants make more money than the junior staff.  You can read the entire article in Bangkok Post.  I did have an older female flight attendant on my First Class flight with Thai airways and the service was great. I wonder what the average age for flight attendants in SAS is like