I have extensive experience of flying mostly Star Alliance over many years and I can tell you that on the majority of my flights on various Star carriers families are invited to board first before any *G or even J Class ( Which is usually my cabin of choice ). Also on my BA flights that has been the case.

Also KLouis has corrected the assumption that these are broken rules with his post. Your comment that *G and Business Class MUST board first is incorrect.Even Star Alliance themselves state Where this is offered.

What we would like to happen and what carriers permit are two totally different things.