Hello and welcome to healthcaremagic Yes,Herpes can indeed lie dormant for many many years.She may have acquired it before marriage Herpes virus once acquired travels along the nerve and resides in the spinal root ganglion where it may lay dormant for months or years. From time to time the virus multiplies triggered by factors like stress and travels down the nerve to reach the surface, either give rise to a clinical episode of herpes OR else it may be shed asymptomatically. It is well-known that most people that have herpes have no signs or symptoms. So it is possible that it has been dormant all of these years. Maybe now that she is getting older her immune system is not as great and it has allowed the herpes to flourish and have an outbreak. Hope this helps Regards