Children appearing twice in census (General)
I'm not seeing anything to suspect duplication. Given that you say these families were related and names were often reused, this just looks like coincidence. I've come across a number of instances where names are the same. It can make it difficult to separate families sometimes.
And I wouldn't call these neighbours as one is in Coalway and the other in Broadwell. Close maybe but not exactly neighbours.
I think you are dealing with two separate families.