Most women mathematicians do applied mathematics because it is easier to get jobs. Often women get jobs at banks. There aren't many academic jobs in Switzerland. In the academic system there, new Ph.D.s are 25 to 35 years old, and people aren't promoted to Professor until at least age 40. And the salaries are very low before that.
Women usually stop before that is possible.
Members of the audience made interesting comments. Before the 1930s there were at least 12 creative women active in the AMS, including Anna Pell Wheeler. After that there was a big gap in the participation of women. Now again they are active. Bordag mentioned that after the unification of Germany, less daycare is provided than in the former East Germany.