This might seem rather strange but I feel that it is important to determine a persons standing with their immediate family.
I once dated a woman who didn’t get along with her siblings. In fact, when her sister-in-law died, no one told her of the death. Instead, she read about it in the paper.
And while not always accurate, sibling relationships are a very good indication of character. After all, if a person is not liked by their family, maybe it is not the fault of the family.