Turns out it was a small kitchen fire that mostly just filled the building with smoke. The kids were quickly gathered up and taken across the street to the University's Spectrum - the indoor Basketball stadium and spent a hour playing with basketballs until they were eventually bussed to the public safety building on campus since they weren't able to go back to the building.
When I picked her up she seemed happy to see me and to realize an end to her dramatic morning. That's a lot for a little one to absorb. She later shared with us over dinner that she thought she'd like to be a firefighter one day. So it must not have been too terribly traumatic. She also seemed excited to have got to ride a bus, and to take home a USU Junior police officer sticker.
She went off to bed tonight without a worry, her belly full of ice cream. I'm just happy she's safe in her bed.