Hi and welcome to the boards
Colds can definitely affect sleep. My DS has just gotten over his cold and his sleep was terrible. He was waking nearly every hour as he just could not settle himself and get comfortable.
I would definitely try to stick to a routine throughout the day i.e. 3.5 hour to 4 hour - which ever one your lo is used to.
If your lo wakes so early in the morning and has a feed - is she tired? When our DS woke at 5:30 we would treat this as a night feed and put him straight back to bed and start the day when he woke up. This worked great for us, as it meant that he usually slept until at least 8:00am.
It is really up to you how you want to do it. If your lo is happy with this routine, then by all means stick to it, if not, then you can work on changing it.
Keep us posted on what you decide and how you get on.