Cindy,
I think the homeschool ought to stop now. That girl needs a taste of real life, and public school. Why should you put yourself out for her education if she is willing to get married before she is even finished with school? This YOU can do. It is completely your thing. If dh thinks them being married is okay, then him teaching her or sending her off to public school is okay too. No need to go to any extra effort on your part, and then when she's in public school there is no reason for her to live in your home with her new hubby. She can live with his parents and figure life out on her own, since that is what she wants. Obviously, your opinion doesn't matter, so why should your teaching.