Yes, sometimes we need to pull back and let people make mistakes. However, when they become a danger to themselves and to those around them we have a social imperative to intervene. There are a number of ways this intervention can occur.
There are multiple solutions to this, including an abortion. The huge problem here is that in FAR too many cases, Joe goes on to have other partners, leaving Jane high and dry with a baby born out of wedlock swelling the ranks of single parent families. Yes, we should help Jane and possibly including sex education training. Joe, if he continues his fleeing drone habits, should be arrested for reckless endangerment for all he has put his partners through. If Joe and Jane stick together we should help them as a couple with sex education training thrown in for good measure.