I may be misunderstanding or misreading into what you are saying, so if I'm giving you advice that's irrelevant bear with me. I'm pretty convinced that this "married in the sight of God" nonsense is a compromise many younger Christians (and sometimes not so young) make mentally to avoid feeling guilty about disobedience. A way of saying that God approves of what would usually be wrong behavior in this case because we love each other so much and love is the greatest commandment. I'm pretty sure there's nothing in the Bible to support the idea that two people can somehow be married super privately in the sight of God and no one else need be informed or consulted. Commitment without accountability isn't worth much, and part of making it public is to have the community there to hold you accountable to that commitment because it isn't going to be easy. Throughout both history and the Bible marriage has been a public social recognition of people forming a domestic social unit (couple, family, man and his multiple wives in some cultures, household, etc). But I am convinced that it's primarily a social construct rather than a religious one and so God gives few specific commands as to how marriage ceremonies should be performed but plenty of commands against violating it.
The other thing I'll say is that the paperwork is there to help protect the commitment, when done right. My co-worker was talking about how he and his wife waited some ridiculous number of years (like seriously longer than some marriages last) to get married because they wanted to be sure that it would work out. I looked at him and told him that was why you got married, to put the legal and social framework in place that makes it so much harder to get out of it that you're motivated to make it work. If you're committed, you prove it by locking yourself in with no way out. And yes that makes it harder and more long and drawn out and painful if things fall apart, but that also just gives you that much more reason to work hard to keep things together.
And though it's not clear if this is part of your situation or not, I do want to state that God has absolutely no modern requirement or expectation for a man and woman to marry just because they've slept together. That's not marriage in the sight of God, that's fornication (ohhh there's an old fashioned word no one uses outside of church anymore because it makes it sound like people are doing something wrong).
And this is not meant to be an attack on Demi in any way shape or form. I don't know her situation or history well enough to speak intelligently about them. It's even possible that she means something else entirely by married in the sight of God than I understood when I heard it. This is just an attack on bad theology that could lead people into sin or foolish life choices because they think that God approves of those decisions.