It's not a mother's job to raise children. For many generations in the past it was seen as just the women's job, but it ain't in the 1950's anymore. It is the parents job to raise their children. Make a sexist distinction is just that--sexist. I was raised by both my parents evenly, and that's the case for plenty of other people out there. Now, looking at Beto's statement itself, he's probably trying to give her more of the credit, which is understandable. Beto's not saying a woman's job is to raise the kids--that's you saying that. And while I agree with the sentiment of the professor's argument, I don't really think it applies to Beto here in this situation. It was a harmless comment at best, IMHO. However, you clearly did strawman her. The prof. did not say that it was not the role of a mother to raise her children at all, she's saying the idea of "suggest that it's a mom's job to raise kids, and having that very unequal division of labor has disastrous consequences for women both at home and in the workforce." What you are saying that she said, is not what she said at all.
