Actually you may have visitation rights. This is especially true since you have been in your stepchildren's lives from such an early age and you are their only living mother figure. However, this is a hotty contested issue and the law varies from state-to-state. At this point, you should consult directly with a local attorney who specializes in child custody/visitation cases.In the meantime, here is a link to a site that will provide more information:https://family-law.freeadvice.com/family-law/child_custody/stepparent-child-visitation.htm