Why would they give to children under 4 back to my worthless sister, and not to me?

No details here but I'm guessing because you're not that much of a sister.

Maybe she was better at explaining herself to child services?

why do you call your sister worthless and what did she do to have her kids taken away in the first place. can you do any better than her and why do you think so . why don't you help with her problem any way. what is wrong with the way she is raising her kids . what kind of parent are you and what kind of problems do you have that can haunt you from your past?

well calling your sister worthless shows you have a lack of family loyalty for whatever reason it also makes you sounds bitter and resentful, hardly a productive environment for children in my opinion. However if this is the decision that has been made and if they are her children then it makes sense as long as she is not likely to harm them in anyway. As a sister and a auntie perhaps if you feel this way you should take time to build a real friendship with your sister stop looking down your nose at her and help her if thats what you think she needs. Standing in judgment hardly helps does it!.

probably because she's the mom (i'm assuming). perhaps she's 'promised to change' or taken the required classes she's had to take in order for them to deem her 'ready' to have them back. granted, a lot of them just keep repeating the same mistakes and end up losing their kids for good, or the kids eventually grow up and leave on their own. it can be frustrating the way the system works...i've wondered about it myself. but...the only thing you can do is be good to those kids when they're with YOU. maybe volunteer to watch them for your sister on occasion so you know they're at least being taken care of part of the time.