This lack of gender equality consideration is a problem, because other leaders follow the CEO's lead. If there's not a focus at the top level, there will likely not be a significant drive at other management levels to increase gender diversity.
HR cannot do it alone; they need the backing and support of others. HR is tasked with multiple functional areas, including recruiting, compensation, benefits, culture and often payroll and safety. If gender diversity is just one more thing to think about, the HR professional will not be able to provide the focus necessary to change the direction quickly or with great impact. Diversity and inclusion are always on the plate of the HR team, but HR does not seem to be the place from which the C-suite can be easily influenced. Given this, HR needs champions in the organization who support gender diversity in leadership.
Formal mentorship programs are effective methods for developing women leaders. They also reinforce corporate values and provide development opportunities that are aligned with the needs of the organization. And they can be managed by HR in a way that does not take a great deal of time or an extensive budget.