It is normal. They all go through what I call the insecurity stage.
Yes, very much so
That's normal. Don't forget that you are all she knows. <br />
My advice: So long as nothing is actually wrong with her, or she needs a feed/change etc, let her go for a bit. Each time, slowly lengthen the time before you respond to her. She will get used to it and be happier for you to leave her for short periods. But remember. It really is normal :)
Don't worry. There are different types of attachments that children have. When you come back, is she easily soothed? This is usually the healthy balance. If she cries when you leave but it easily soothed when you come back, she has a very healthy attachment. If it's hard to stop her crying even when you come back then she might have an insecure attachment but with encouraging her to spend time exploring by herself while you are in safe distance then that can balance out too. :)
that is soooo normal.