URGENT! Please help me! I don't know what to do

Hi Guys, I am from Colorado and this is what happened yesterday. At a ski resort, a lady and my wife got into a fight (apparently my wife got on her way while skiing), the lady started to get very violent at my wife, who knows martial arts and pushed her. The lady fell, my wife kicked snow at her and I had to get between both to stop it.

The lady called the cops, they filed a report and called my wife to the police station tomorrow morning to talk to her about that. She already gave her statement yesterday, so it seems like they called her to clarify a couple of things, since her side of the story is different than the lady's.

My questions are:

1) What are my wife's rights at the interrogation session? Does she have to answer the questions? Should she go there with a lawyer?

2) What is the worst that could happen here? From my point of view, there was no need to get the cops involved as it was a minor problem, but I don't know how deep in trouble is my wife in.

I would really appreciate some input here, since this never happened before and we are a little bit scared.

Thank you!!