I am pretty sure that most men do not negotiate salary either. It is hard to believe that a significant percentage of pay gap between sexes is determined by negotiation skills. And the whole "don't take the first offer" thing is just silly, though it may work in case the first offer is really bad. Going by the title of the article, if the offer is 'good enough' for you, you should take it.

As lots of posters have already said, the solution to work-life balance is not more benefits to working mothers. It is more benefits for everyone. Paid parental leaves for both women and men and more time off.