Family
My family is simple. I have my sister, Narcissa, and my husband, Rodolphus. I suppose that my sister's husband and child are included in that, but, personally, I don't consider them as such. I wouldn't die for them the way I would die for Cissy or Rodolphus. But don't tell Cissy that.
I suppose I would consider the Dark Lord my head of family. I'm sure he would laugh at me for that "fanciful notion". I am not naive enough to think that he considers me in the same light. But everything I do, I do for him.
My husband understands, being a Death Eater also. Some of the fellow Death Eaters whisper that I can't possibly love Rodolphus because I am so devoted to my Lord. But Rodolphus and I know the truth, and the nights we spend together prove that. I love my husband, and would die for him, as I would die for Cissy and my Lord.
The whisperings amuse me, though. They prove that my fellow Death Eaters know nothing about me. Not even duty to my family line would convince me to marry someone I wasn't at least fond of, for Merlin's sake. And the love I have for my Dark Lord is quite different than the love I have for my husband.
As far as the rest of the people in my life.. They are not family. I wouldn't hesitate for a second to sacrifice them if it would save one of the three people I love or myself. I'm sure they already know that, though. And if they don't, they'll find out at the most inopportune time.