Need to know what others think

I am in a Psychology class on the internet and we meet in a chat room one night a week and do an assignment....after we do our discussion one person is supposed to type it and post it. Well, in my chat it seemed that one person didn't seem to be pulling her weight. It was her turn to type and when I aksed who was typing she popped in that she had to work. I just stated that I wanted to make sure everyone did their share and that i would be glad to do it if she wanted to take up the slack later on down the road. She cam back with "I'll do it!!" Then when there was no chatting for about 2 minutes she said well I have a pen for motes so lets go. I left my group. I told them that I thought I would go ahead and do this assignment on my own and would probably continue to do my own work because i really just wanted everyone to do their share and did not need the attitude. I felt like she was basically riding our shirttails to get her grade. What do you guys think? I believe I did the right thing, but what would you have done? I did write to the two who had nothing to do with the situation and apologized and told them how i felt. I also wrote my teacher, but i did not mention specific names....thanks for letting me vent