You appeared to me to be pointing out that you are still youthful after having several children. If your intellectual merits are your only source of power and authority, your youthful appearance as you age is a red herring

Men have the same discrimination. Youth implies inexperience, and there is no way around it, because by definition you are inexperienced. I dont think its unique to women. Women have an advantage over men in the workplace because not only is their presence more valued (because of beauty), but it is socially acceptable and even expected to be disagreeable. A woman with good looks can use the "bitch factor" or "motherliness" to command peers and inferiors and show an innate ability to manage. Women tend to be more organized at work, and focused on what others are doing. This gives them good managerial ability. If a woman also has competance in the field she is managing people in, she becomes a superstar and consequently can command higher pay if she is not torn by familial priorities.