The bible gives three possible ways to get to heaven.
The first is don't violate your conscience. The second is don't violate the law the third is accept salvation from Jesus. (The first 2 are from Romans 2:12-15 the third of course is John 3:16)
There is an age of accountability, where the conscience is developed enough to know right from wrong. If a child dies before that age he will go to heaven. If he dies after that age then we have to ask if he violated his conscience. Since everyone has we need to check option 2
Did the child obey the whole law (God's law not mans')? Since only one person ever obeyed the whole law (and it's impossible that anyone in the last 1930 years was able to) we can move on to option 3
Did the child accept Jesus as Savior?
Since all men are sinners and have fallen short of the glory of God then all men need a savior. No one has managed to get into heaven by option 2 (although it is theoretically possible, due to man's nature it's out of our reach) and no one with a developed conscience has ever made it to heaven by option 1 (every one violates their conscience sometimes) then the only way to heaven is through Jesus Christ.
Now if these girls were immature enough that their conscience wasn't developed yet then they will have gone to heaven. If they had a developed conscience then they went to hell (unles they were already Christians). Note that it's not whether they cared about religion. It's about whether they understood right and wrong.
Jews, budhists, islamics, pagans, atheists, non-Christian church-goers (Catholics,baptists,pentecostals, presby's etc who do not have a personnal relationship with Christ but who attend church), non-Christian mature children of Christians, all go to hell. Only by faith in Jesus Christ as your Savior can you get to heaven.
The lesson in this is to be sure that you are ready, that you have repented of your sins and made Jesus your Savior. We also need to be sure that our loved ones are ready. None of us is promised our next breath. We have only this chance to grab onto Jesus and get to heaven. We had better take advantage of it, hell waits for those who don't.
God Save America (Please)