My daughter is 7 years old & recently started talking down to me. She has worst attitude to only me & her little sister is doing it now too. When they talk to anybody else they are as nice as pie, but when it comes to their mother, they hate me. Why the sudden change in attitudes?

Louis Bates has a series of books based on ages, such as Your Seven-Year-Old: Life in a Minor Key. The series is a bit outdated but might give you some hints and helps. Of course, go to the library to find this book and others that will help you figure out what is going on.

Listen to how you listen. If you hear yourself talking when you should be listening to her, then you have your first clue.
Next, note whether she has new friends. Outside influences.
Observe her eating habits for proper nutrition. Children need dietary fat, not so much carbohydrates and plenty of protein. Improper diet, exercise and hydration can have an adverse impact on brain chemistry.
Accepting parents convey acceptance to their children. Be careful of over or under-control and be a good listener. And encourage curiosity. Hug. Read to her. And forgive her. She doesn't really hate you. She is responding to something. When you figure it out, you will both be happy. Make sure she is getting rest, and limit violent TV, movies, video games, angry and hateful conversations and condemnation in general. Teach kindness and caring.
Well, you get the idea. It will work out.
Good luck
Mark

My 7 year old has a very special relationship with her father. We have been divorced for over 5 years now and we have 2 girls together. But my oldest is only one to have such a close relationship with him.She gets a twinkle in her eye and a almost giddy attitude when he calls. Is this normal?

What do you mean by normal? Are you inferring that there is something inappropriate about the relationship?

If that is your suspicion you really need to consult with a professional to protect your child.

Also your two posts should be combined - one gives info which is helpful to the other.