Rescuing a Baby Dumerils

[VanSickel_Balls]

I'll try to make a long story shorter:
My sister-in-law acquired a baby dumerils from a local guy, because she works with his wife and was told about them. Apparently, the wife was already concerned, because her jerk of a husband has been so careless with snakes in the past, and has let previous litters just die because he doesn't want to make the effort of feeding them, let alone separating them, heating them, etc...He basically keeps the breeding pair together 24/7 and occasionally notices babies have been born. So my sister in law took one in. Under her care, her little lady is thriving!
Fast forward: my sister-in-law texts me saying her friend at work informed her that while 3 of the babies are still somehow alive, after never having had a first meal at just over 2 months old, one has recently died, she doesn't believe the rest will last through winter, or much longer at all, especially under her husband's care. That's where my husband and I come in. Apparently there is a wee "runt" who is about half the size of the others... and we are going to try and save him along with one of his siblings.

My main concerns... these babies have never eaten before, and I know its a risk taking them on. Dumerils seem to be picky, finicky eaters already, and this doesn't help things...
I want to give them time to settle in, but they've never even eaten before, and it looks as though food soon is critical. Does anyone have any advice or words of wisdom? Any experience with bringing back a failing dumerils in the past? Anything would be appreciated, thanks!