I'm pretty sure that Sakura isn't Sarada's mother, and here's why I think that! Sasuke and Sakura both have strong genes, because most of Sakura's traits came form her father and were only lightened up because of her mother, Sasuke obviously has the strong genes of his family line, if Sakura is the mother, why does Sarada look a lot like a mixture of Karin and Sasuke? Not to mention, the Uzumaki genes aren't as strong, hence the fact that since Naruto is supposed to be a Namikaze that his children took on the genes of his father, Minato, and some of the genes of Hinata, since it's obvious that her genes are very strong as well. It's normal to pick up the word phrases of your parents because of the fact that you hear them say it a lot, and Sakura says it a lot. Have you also noticed that Sarada acts a lot like Karin? I want to see what will happen in the chapters, but until then I'm staying true to my theory.