Viv,
Thanks for sharing this with us. I am sure it was not easy to do.
Unfortunately, a lot of people who do not want children are more focused on, as you politely expressed it, the "HOW". Fortunately, most of them, when presented with the little bundle of joy, turn out to be pretty good parents. Christians have no monopoly on parenting skills.
Christians have all the same problems everyone else has; we all live in the same world with the same distractions (sins, if you will). Christians who have really put some thought and effort into their religion know that the New Testament is focused on one thing...love. They have also learned that it is not their place to judge others. Being judgmental is the biggest problem most Christians have in their relationship with other people, including other Christians. Christians also realize that they are sinners...everyone is. That realization is the reason most of them became Christians in the first place.
I don't want to be judgmental (it's very difficult to refrain), but I suspect the problems with Danielle's family did not start when she met Tony. Her parent's divorce - something that most Christians try to avoid - is an indication of earlier problems. Now that everyone's position has been staked out and documented in the e-mails you shared, I think you are right to encourage Danielle and to "love Danielle...and be there for her when she needs a reliable, intelligent, trustworthy adult to go to for advice and help."
I wish you and your family - and Danielle's parents - the very best.
Mike