k, so it was kinda hard to follow what you wrote but i think i got it figured out. worst case scenario of putting the pinky back with the mom that i can think of is that the mom eats it. mice will do this to their young on occasion, especially if they get stressed while giving birth. other bad case is that the mom just leaves it to die, which is what would happen if u left it in the snake cage as well (either by being eaten or by starving). since the pinky can't really cause any damage to your snake i don't see how any harm can come of you leaving it in the cage with the snake but by the same token if the snake isn't hungry you prolly shouldn't feed it. I usually wait for signs of my snake "hunting" before i go pick up some mice to feed it so that I don't run into the issue of the snake not eating.
as for the snake "giving" something to the pinky, i'm assuming you mean some scent that would make the mother reject it. This is more likely to happen from you handling the mouse than any contact the snake may have had, but either way you prolly shouldn't worry too much.
