There's a fresh, steaming pile of "oh look, sexism" on the internet (when is there not? but this is particularly noisome because it comes from high-level publishing professionals and authors). I can't do much to help clean it up, but there's one thing I can point out.
This weekend I was at a con and had a lot of fun, and talked to a lot of people I don't know. Two different women I got into conversations with (at different times) kept referring to men generically. One of them even said, "Men don't have the tastebuds to appreciate chocolate."
What? Seriously? Yes, she was serious.
There's an artificial wedge between men and women in our culture. Any time someone says "men can't" or "women don't," whether the generalization is meant as a joke or compliment or a real observation, it hits that wedge hard with a hammer, driving it in deeper.
But in real life, instead of in the cartoony headspace some people seem to inhabit, people are individuals. Saying stuff like "women don't understand math" or "men don't have any fashion sense" is stupid, because it's not true. Some women don't understand math. Some men don't have any fashion sense. But not all of them--not even close.
Don't hit that wedge. Don't say stupid stuff without thinking about it first. Most importantly, don't teach your kids that the wedge is real, because goodness knows we've got a hard enough climb to reach "people are individuals and all deserving of the same respect" without that big old wedge getting in the way.