Hello,  I can feel your pain in your question.  As a parent of older teens I know this is near my top of the list of "greatest fears" because you have been this person's support and sole provider and now you are an "outsider".  I agree that counseling for your family is warranted.  If nothing else to give you and your family members a way to vent and not strike blame.  If nothing else, go yourself.  You are grieving.  You have experienced a tremendous loss and shock at a time when your daughter wants you to show loads of approval for her "grown" up decision.
 
Second, try to bring this couple closer than further away.  Be supportive without supporting them fully.  Invite them for dinners, bring over prepared meals, help show her how to care for the house. Give her some used furniture or a tv set to help them "start" on their way.
 
Also, the more you get to know her husband and he comes to trust you and your family the easier it will be for your daughter.  He may have some positive qualities that you don't quite see yet and getting to know him and his family better help all of you.  See what are his interests and try to become involved. Perhaps he loves baseball and all of you can take in baseball games together from time to time.  Also, if he likes you then you can have alone time with your daughter and listen to her in times of need (or joy).  Baby steps to help your relationship will be needed over a period of time.
 
Help her to stay healthy.  She may need to consult with a doctor about issues regarding her personal health and methods of birth control.  Also, she is at an age when booster vaccines are given for a variety of illnesses, and she may need to ask a doctor if she should receive these at this time. Also, establishing a relationship with a health care professional will give her someone to help her if she should encounter a personal crisis.
 
As for her education, you may need to let her know about her options, but then it is up to her to make choices. However, please don't shut her out. Sometimes older teens think they are adults and will be impulsive when a notion seems so romantic or exciting.  However, reality is bound to set in sooner than later and she will need you then more than ever.
 
Good luck and please let us know about your family.  
 
Regards,
 
Louise Masin Sattler, NCSP
Nationally Certified School Psychologist
Owner of Signing Families
http://www.SigningFamilies.com

Unfortunately, all you can do is try to be there for her in any capacity. Experience is the only teacher to really make her understand. Sometimes people change for the better too. So maybe having a more optimistic outlook would be better mentally for both of you. She is now considered an "adult" and that is also a hard thing to grasp. Here you have raised this child and watched her grow up only wanting the best for her. What she has planned for her life is now different than what you want and had planned. I hope you can realize that she needs this time to learn on her own. So let her. As hard as it will be and is, she will eventually come around to what you have taught her. Good Luck