hi Tammy
I have some questions for you before we can help get you back on track!
Firstly I need to ask why you are trying to extend her A times to 3 hrs? It is because she has dropped the catnap so is awake too long in the afternoon perhaps?
What A times does she normally do? What's her usual daily routine?
How have you extended her so far?- some do 5-10 minutes every few days really gradually, but some lo's cope with a big leap of 20-30 minutes in one go. It's importnat to judge this right to avoid overtiredness as that'll cause you all sorts of problems.
How long has she been waking at 5.30am? What do you do when she wakes at this time?
As for today, I would definitely offer another nap. If she doesn't take it go for an early night.
When my dd has a cold she always wakes earlier in the morning, I think because she has trouble breathing through her nose so coughs and when she comes into a light sleep around 5-5.30ish it wakes her. Once the cold has gone she gets back on track pretty quickly all by herself.