Instead of allowing the situation to blow up I encouraged my younger coworker to smooth things over with our older coworker. Unfortunately these situations keep happening. Should the younger person always defer to the older person? At what point do you tell someone older about themselves? If you tell them off, are you being disrespectful? Was I wrong to tell her to defer to our coworker?
If the coworker was going to stay, I would not have encouraged the deferential role. Sometimes you have to let people know how you feel and let them know that they are wrong. You can do that in a respectful manner by being forthright and direct. But don't expect the person to change their behaviors. They will probably just change their interactions with you.
As a young lady I was raised to be respectful to my elders and I usually am. I just hope that when I get older I remember how I felt as a young woman. I want to remember that I am not infallible. I want to continue to learn from the young. I want to be that foxy older lady. I want to age with wisdom and grace.