Can't say I've ever experienced this, but the sister of a family friend had 5 kids and due to a number of extenuating circumstances (I think drugs may have been involved, but I'm not 100% sure) she was deemed unfit. The oldest (17 at the time), and the two youngest (about 6 and 10) went to live with our friend (who already had two kids) and the middle two (maybe 12 and 14) went to live with her mother.
The 17 year old hated it here (they all came from the city and we're a small town) so after they couldn't make it work, he went to live with his grandmother too until he was 18. Not sure what he's doing now. But the two girls are still here and involved in our Church (one of them is in my youth cell group - the other's too young at the moment).
Our friend's family was raised Catholic, but I don't think anyone outside of her parents - and maybe one or two of her siblings - actually took it super seriously. The kids in question certainly didn't really have any particularly faith upbringing (their dad is... Indian I think...), so the girls being here has done them a world of good in that regard.
I can't say I know of any life lessons, but as long as that child is in the right hands, it will be a good (better?) thing.