I can't help much but I imagine that this is going to be very emotional for all of you - helping her to navigate these uncharted (for you) waters. If I were in her shoes, I would want my sister to have her listening ears on, plenty of hugs, boxes of tissues, my fav comfort food, and some distractions. Whilst it IS important to get her checked to determine her EDD and so on, it will be very hard if everything is made to be about the baby.

I think you're an awesome sister to be so concerned and looking out for her. I hope her BF stands by her and the baby.