Ofcourse, you are 100% right without a doubt and I am glad you brought up this story before Purim. Maybe it will have an impact on readers and they will remember it if the situation arises this year in shul and they will have the proper manners so as not to hurt someone who is in the situation you were in at that time. You are teaching a good lesson at an appropriate time. Kol Hakovod to you.
For those who do not understand this, I feel sorry for you. There is no excuse for NO ONE offering her a seat. And the issue is not WHY she came just in time, the issue is what middos were these young women taught if they did not have the common sense to do so?