Yorkiegirl, sympathy from me, have potty trained dd this year whilst bf ds, it's bloody hard work (and involved a few dashes with potty in one hand whilst holding bf ds in the other). IT WAS NOT YOUR FAULT SHE WEED ON THE CARPET! That's part of potty training. Just being in the room means nothing anyway, when the child only realises when it's coming out you can't always get there in time.
katierocket it spot on, wine and choclate for you and lots and lots of reassurance for dd, it was just an accident and the last thing you want is her getting upset over it.
Good luck!!