Thanks!
What I've done is boil the water in advance and let it cool, filled all 6 bottles and refrigerated them, then when shes hungry I add the powder to a bottle of the water, and heat for 4 minutes in my bottle warmer.
Quick and safe and by the rules!
You need to add the powder to water that is at least 70 degrees, formula isn't sterile so adding to 70 degrees water kills off any nasties