facepalm at this whole thread.
So even GF doesn't advocate strictly following a routine when baby is ill... but you're wondering about it. You do realise she's at one extreme of parenting ideas - and by pondering this you're even further along the continuum than her? Does that sound like the ideal mummying recipe for a rounded childhood?
Do you personally eat at exactly the same time of the day EVERY day, fall asleep at exactly the same time EVERY day - even if you're feeling ill? Or do you maybe nibble smaller more frequent meals because you don't have much of an appetite, tend to doze if you're feeling crappy or worse lie awake at night because you can't breathe and it's so annoying. Its probably more than annoying for such a wee baby it's probably a little bit frightening. Have some humanity.
My DS (9 months done everything wrong according to the books ;) ) has just had a tummy upset - he's needed feeding little and often amounts of breast milk (the only thing he can keep down, you'll have to buy lactose free formula if those three hourly routines have scuppered breastfeeding) and he's needed feeding every hour. That's every hour day and night... on NHS Direct orders not those of some woman who's got no childcare qualifications, certainly no child development or medical ones and has never been a mother to a single child. Imagine what that will do to your well thumbed schedule.
That book simply does not work in real life, with things like viruses and teething pains, and little tiny babies having a bit of a bad day in it. I'd use this as an early wake up call and bin that book.
Or you could use it to prop up one end of the cot.
Oh and the crying techniques mentioned above don't work on such a small baby. They are too young to LEARN anything with them. Dear god at that age when you leave the room they genuinely think you've gone for good. They stop crying because they are knackered, not self-settled, just knackered... and probably hoarse.
Please let your baby be a baby and stop demanding that it fit around some schedule that's convenient to you. Babies are pretty inconvenient I'm afraid.