If both parents leave the joeys all alone for more than 10-15 minutes at a time and do not respond to their crying, they are likely rejected. Examine the joeys for any facial scratches, do the tent test to check hydration, see if their tummies look full, and make sure they feel warm. Young joeys can die of hypothermia very quickly because they 100% rely on mom or dad for body heat. If they are being left for more than 10-15 minutes they are probably getting too cold. If the tent test looks like they are dehydrated give them some water in an eye dropper or syringe now, and get unflavored pedialyte and start using that instead. You must be extremely careful when feeding small joeys, do not shove anything into their mouth or they can inhale it and die. You put liquid on their lips and wait for them to lick it up. If you pull them you will have a very rough time for the next month, and it is always better to simply supplement feed and babysit them if the parents are being nice, but just tired. If they are truly rejected and you don't pull them, they are more likely to get hurt or killed by a parent though. Sit in the dark with them for an hour or more and have enough light that you can see which parent(s) are out but NOT enough to disrupt their playtime. Be quiet and observe; if the joeys get left for more than 10-15 minutes, reach into the pouch and feel them. If they feel at all cold, that's bad. The main concern is that they stay warm, hydrated, and fed. During the day the parents will keep them warm as they all share a pouch. Oh, I would remove all extra pouches and hiding places, so that the parents' only option is the pouch with the babies. The general rule is that if you see wounds on the babies faces they are probably rejected. All four joeys our mom has had have had the exact same sore next to their eye in the exact same place at the exact same age- curious, right? It went away with antibiotics and was not related to rejection. So, use your judgement. If the joeys are warm, hydrated, and fed, and are not injured or being ignored, you should be good. Keep a close eye out. First time parents often make many mistakes, but that doesn't mean the joeys are safe if they make the wrong mistakes.