When he asks what she hung up, she says mistletoe. What is hung up is holly. A common mistake in a lot of Christmas movies.
The address of 'nana and Drew's house is 7330. Lana's house across 'the street' is 9147. Which is actually almost 20 blocks away.
Christmas in Chicago but the trees are still filled with green leaves.
The morning after arrival Drew is decorating the outside of his Nana's house; but the night before the house was already decorated.
Drew is over a foot taller than Leah. When they are standing in front of the gazebo at the end of the movie, they appear to be closer in height in close up shots. When the camera is further away, the height difference is correct.
Leah's friends, Marcie and Kendra, ask Leah to volunteer at the grade school fundraiser. Leah told Drew that Marcie and Kendra's kids went to that school.
Later when Julia and Leah are in Kendra's store to look at a possible wedding dress, Kendra mentions her boys are two year old twins. If they are only two they wouldn't be in grade school yet.
Paul and Julia arrived at Chicago O'Hare International Airport. Her luggage tag should have been marked for Chicago not Roselake.