Really??? So basically all parenting ends at age 18? Having a baby out of wedlock with a girl whose biggest ambition is working a minimum wage job is a decision that he will have to deal with for the rest of his life.
Parenting does not end at 18.
However, your the ability to call the shots does end at 18 or at the moment that your son left your home and your budget to begin a life of his own.
It is naive to believe that we can control our kids forever and what will happen when you attempt to call the shots on whom your son can date, you will find a reality worse than you could have ever imagine as even adult children will rebel against controlling parents.
You had your opportunity to raise him (or his mom and dad did, not sure!)--under your guidelines and expectations from age 0 (or whenever you arrived) until age 18. He now has the chance to spread his wings and fly and as long as she isn't breaking any laws or encouraging him to break laws, it is truly honestly best to stay out of it unless he solicits your opinion.
It seems crazy and hard to do especially since you have admitted to running your home from the Christian perspective and it is heartbreaking to watch the kids leave that.
Noone is saying you have to like or endorse or even approve of what he does.
All we are saying is that he is a grown man and the more you try to control anything that he does, the less likely he will allow that to happen.
You know--you attract more bees with honey. And often the quickest way to get rid of someone sometimes is to fawn over them. If the relationship isn't serious, it tends to die off quickly.
My sister and brother were both in relationships that were abusive for one (sister) and toxic for the other (brother).
It was difficult to not say anything when we had no facts. And in my sister's case at least--she wonders why noone would say anything. But honestly, she woudln't have listened. She had her mind made up and at least in our presences, her DH was okay. Not someone I would date, but no red flags went off that said run for the hills. I wouldn't have suggested she married him, but it wasn't my place to stop it either. Sometimes people have to make their mistakes. Only when there is danger do you intervene. In her case, we had no idea of the danger until after all was said and done and they were married and she finally left him.
I'd also stop trying to convert her. It is okay to have her come to church or witness your christianity in action. It is entirely different to be recruiting her (if that makes sense..I can't think of another word.)