The idea of the EASY routine is that it is not a clock based one, but an order one, so if your baby wants to sleep later, let her, but then shift back everything else in the routine.
Somewhere, TH did say that before you start a routine, you should observe your baby's natural rhythms, so that the routine is based around your baby, and not the clock. As your baby grows, the routine will need adapting, but she recommended just taking a day out to observe your baby when things get out of sorts, and then re-adjust your routine.
If you do have a look at her website, she does make some things a lot clearer that I think is not very clear in her book (like she does not recommend PUPD for young babies, and then only as a last resort etc).
However, I used her routine and found it to be great. MY DD quickly learnt to fall asleep herself and I never had issues of her wanting to be bfed to sleep, or getting dependent on any other sleep cues, so it really worked for me!
HTH