I think a lot of times these older gal's (70's-80's) are there more for the public relations of it all rather then actually working. Several years back, I was on a DL
flight that had a very old (I think she was in her 70's) F/A. All she did was go around and ask people if they needed pillows, blankets, etc. The other F/A's worked the trolley, served meals, etc.
One time on UA
, we had a F class F/A who had to be in her late 60's. It was on a 727-200 and she worked the entire section by herself. She was just wonderful. Great attitude, lovely manners, you felt like you were being served by your own grandmother! She also wore a LOT of "Jungle Gardenia" perfume! When the flight was over, we thought that maybe she would give us all a hug and a kiss goodbye! She didn't though. Very enjoyable experience!