No, you are not over-reacting.
Clearly she is not a friend. It's interesting to me because I really found out quickly who was a friend and who wasn't when I began recovery.
I remember having a feeling like you were talking about. I was about 3 weeks sober and went to a neighborhood party. I didn't drink, but felt anxious and really miserable. I went home and the next day I went out and bought a bottle of wine and drank it.