Ryan you cant just look at someone and see with your eyes they are virgins. Now if you are talking about and adult women who has had several children and she stands directly in front of you stark raving naked then yes you would see a difference in the way the breast are after nursing and the vagina area changes shape after childbirth. Now one must say artificial insemination changes this and she might well be a virgin, but have had a child! LOL
Lets just say that if you looked at an old women like me who has had 3 children there are definite physical changes that would tell you! Yes this women has had children. certain parts of the body move and change shape not always bad but pretty much changes visiably!