What is the name of the book about people who lived in a museum like city where they had to live like they where in the 18th century and then a virus breaks out and they people who run the place won't let them have a vaccine so the girls mom tells her about the "outside world" and she has to go and get a vaccine for the virus?

This is bugging me so much!

I also remember that it had a picture of a girl wearing a smiley face t-shirt on the cover.
Nvm I just rememberd.

It is called Running out of time.