Jo P. Thanks, I understand that. I just feel that unless I have raised the dog myself from a pup, I can never be totally 100% sure of it's history or how it's been socialised etc. As I have young children, it is not a risk I am prepared to take, no matter how small.

Lots of rescues, including the better known responsible ones, will not let those with children under a certain age have any dog, and those with older children wil be limited aswell. That is for a reason.