Peer mentors are colleagues within your own department who are at relatively the same stage in their careers as you. They are excellent sources of academic collaboration, clinical coverage, and moral support.
In academic medicine, promotion criteria are universal, regardless of your specialty. So in your search for senior mentors, you do not have to limit yourself to your own department or even your discipline. You should also develop resources and contacts in other departments at your own institution and in your own specialty at other institutions, both regionally and nationally. The added benefit of talking with mentors outside of your department is that your personal maternal-child health experiences will not impact them directly. They won’t have more overnight call because you are having a baby, but they may be able to give you institution- or specialty-specific advice that you might not have access to from within your department.