absolutely, completely normal....
7 days ago she was enclosed inside you, and she just wants to be as close to you as she can - its her instinct.
She is not "demanding" to be fed - she NEEDS to feed, to get your milk supply going. THis is NORMAL and necessary.
I would say feeding every 2 hours is much more common, so if she is going 3 or 4 hours, that is quite a long time.
I know it is tough, and that you will be going a bit crazy with lack of sleep, but this is what it is going to be like for a few weeks.
Eventually, she will differentiate between night and day, but at the moment, she has no idea when she is "supposed" to sleep and when she is awake. She has absolutely no idea that she is even a separate person from you!
YOu have to just hold and cuddle her to make her feel safe, otherwise she will indeed cry.
Its OK to do this, and its OK to let her sleep with you or on you, if you want to co-sleep.
Hang in there
- it is VERY early days yet! Btw, do you have a partner who can do some of the baby-holding? DH and I used to just take it turns to hold, while the other ate/bathed/etc.