On pages78-80 the longest blackout in Ember history happened for 7 minutes and Lina lost Poppy. Luckily after the blackout Lina found Poppy.
On page 133 Lina goes and finds the doctor to help Granny who is sick. The doctor states "I can't promise to help her. I am low on medicine." So that is a problem because if anyone gets sick there is no promise that there is medicine to help.
The Mayor is Stealing
On page 143 it says that more stores every day are closing or only opening on few days. This is most likely happening because of a shortage of supplies.
On pages 150-154 we learn that Looper is stealing valuable and rare items from the store rooms, and nobody knows about it except his girlfriend Lizzy whohe is sharing with.
On pages 156-157 the mayor is in a room in the pipeworks asleep. This room has valuable goods from the store rooms, and no one knew any of those items were left.
On page 157 we learn that there had been 5 blackouts in one week. That is a concern because it shows that the generator is failing.