During the opening title sequence Crystal is Christmas-shopping and takes out her iPhone to loot at her shopping list via the iPhone-notes app. Although nearly every shop sports Christmas window-displays, the phone shows "Today 31 Mar" in the note.
When Crystal opens and reads the Santa-Claus letter, neither has a return address; in the next scene, she tells her friend she Googled the return address.
Scenes alternate from much snow on the ground to scenes with no snow at all. The most glaring example is when Crystal first visits the Gowen house to drop off Olivia's glove, there is at least a foot of snow on the ground; by her first visit to the soup kitchen, every bit of snow is gone.
When Crystal talks on her iPhone, the display is clearly still on the home screen.
When Crystal opens her mailbox and looks at the stamped envelope addressed to her, containing a check from her parents, the stamp has no postmark.
At the beginning, we are led to believe she owns an apartment on the Upper East Side in New York called "The Germain Residences" however the building that they used is in Calgary, Canada.