Should I march right over or let it over to him?

I wrote here before but think I have gotten to a decision myself. Time will only tell if it is the right one, I suppose. My child complained that a female work colleague of her dad has been rude to her. She has said she thinks it can be because the woman is maybe stressed out. Same woman I have my reasons to think she has had the hots for him before. Our daughter knows nothing of this, we haven't told her. I never confronted the work colleague about it at the time, but I did him and he denied it. I was mostly back then let down by his behavior at a work function before where she too had attended and she had this glott expression and behavior to her, looking my way, when he should have gone over to me. I know it ain't much to complain about but it bothered me. It was the final emotional punch after hours of attending that thing, and him acting weird. He would tell me he was nervous. One way he had seemed very focus, another distracted. He gave me zero attention. I had not even asked to come, I had only come because he had asked me to, and then he acted as if he had no interest at all that I was there. He would later apologize but before that he took defense and was making everything worse.

My first instinct when hearing this was to contact the woman to tell her to lay off being rude to our daughter. Though because of the past I know that once I confront her I will most likely see red because of how she behaved towards me at the work event now long ago. I won't be able to keep those things apart.

I've decided our daughter has to tell him and then see if he does something about it, that is if she even feels like telling him. At the end of the day this is about their father-daughter relationship and someone at his work, and I should not have to be involved. Then again i think my daughter should say something to her dad about it, considering that woman can with her rudeness make it so that our daughter hesitant or avoid all together to call or visit her dad at work, if, when he would want her to in the future. That he has a right to know.

If anyone else has any other suggestion, please let me know :)