No, breaking the queue and stepping in between from nowhere is not acceptable. This is the problem of the society that it is filled with laws and support mostly for women only, in the name of feminism a lot of women are misusing their rights.
It would not be wrong to say that the lady who broke the queue was a feminist who didn’t care about anything else in the world and stepped in between and said that she is allowed to do so.  Oppose such activities and make equal ethics.