Sakura is by far my Favorite character in Naruto... I have my reasons why but back to the topic

. Sakura is a Normal Girl who only attended the Academy because she wanted to get closer to Saskue. As far as her Family goes I read that there Anbu or something. I highly doubt there Civilians. In the manga Shikamaru said that Sakura's parents would want to take revenge too if she got killed ... which makes me think that her parents are in Anbu which is why we dont see them or hear of her family much. Sakura speaks about her family in the Anime/Manga alot but never goes into details. And there are Scenes when Naruto's sitting on the swing crying of a girl with a red ribbon in her hand holding a male's hand(SAKURA). So honestly I think her family are part of Anbu. But she does Hold a Crest. Dont think its a family crest. Just think it represent Sakura and how she is.
Sakura flower(Cherry blossom) is an omen of good fortune and is also an emblem of love, affection and represents spring. Cherry blossoms are an enduring metaphor for the fleeting nature of life, and as such are frequently depicted in art.
And if you noticed. Sakura's tends to cry in her room looking out the window at full moons. lol!
I <3 Sakura Shes my favorite character