I read her books and found her to be so utterly, infuriatingly SMUG. One anecdote she gave in her book is of sitting in a GP waiting room and a mum was noticing her baby was working up to a cry. She fussed over her baby, offering toys and whatnot so Baby Whisperer lady said she went over to this mum and 'introduced herself' (presumably as "oh hi, I'm Baby Whisper and I'm about to put you in your place by telling you I know your baby better than you do..." and proceeded to tell the mother that her baby needed to sleep and what she should do. She did not go on to say this poor mum lamped her, so I guess she was more polite than to do this, or come back with a 'Fuck Off, thank you'.
In another charming anecdote, BW says she was called in as aconsultant with one family and the baby starting to cry. BW said she took notice of the ambient temperature, any sounds around, sniffed the air for any strong odours which can upset a baby, whether the baby is perhaps comfortable, warm enough, where there any bright lights upsetting the child. She then asked "when was the baby last fed" and sure enough, infant was hungry. Well fuck me, I'd have asked that question BEFORE checking for noises or strong odours.
So I used her books to prop up the mattress in DS's cot when he had reflux, so I did get some use out of them.
Honestly, the EASY routine is a pile of poo. What do you do when your baby wakes up after 15 minutes into it's 45 minute nap? it throws everything out and you can't feed on waking as it's too soon.
You will fall into a pattern with your baby. It just happens. And they can also learn to fall asleep without any parenting gurus. No one is rocking their ten year old to sleep.
Remember that the authors of these books are less interested in helping you and your baby and MORE interested in being the leader of a new method of parenting and becoming a household name. Take note of the titles they give their books - all exaggerate their ability to help you soothe, settle, control your baby. Never mind that a 0-3 month old is a chaotic little creature that has no routine nor can it build one yet.
Follow your own method or alternatively read ALL the books to get a fuller picture.