nanette
congratulations on your new baby. you must be very proud and pleased.
at five weeks she is still very young, and there is plenty of time for her to settle into a routine.
if you are up to it, i recommend that you search on the mumsnet boards, you will find plenty of advice and - er - "commentary" on GF's routines and how they work (or don't) for young babies.
i would just go in and give her a cuddle if that's what she wants - she will only be a baby for what will seem like about 5 minutes! so try and enjoy it, if you possibly can, even though you must be extremely tired atm.
i recommend you ignore the tone of the book, plenty of people posting here (including me) have used the routines sucessfully without following them to the letter, starting them later on etc. do try and search the boards if you can - plenty of tips and reassurance there.
when my ds is being a bit clingy, i just remind myself of all those times in the future he's not going to want to know me and make the most of it!
i know this advice must seem really patronising. i got similar advice when my baby was about the same age as yours is now, and that's what i thought then. but with hindsight, i can see how right it was!
good luck!