When Sandy tries to get candy from the machine, the position the candy gets stuck in changes.
When Jennifer Aniston jogs up to the playground and starts talking to Kate Hudson and Britt Robertson, she pulls out her earbuds. A minute later, they are back in her ears as she continues to speak with them.
In the park scene towards the end of the movie, Russell's mother arrives in a silver sedan. The vehicle clearly runs along the curb as it comes to a stop, but the very next frame shows her exiting it when it's several yards away from the curb.
Russell's mother calls him from Las Vegas when they're in the runaway RV. The same day she calls again, celebrating Mother's Day in Georgia.
Dana Barton's headstone says "LT Dana Barton." Though the movie never states her pay-grade, USMC abbreviated ranks include "2ndLt" for an O-1 or "1stLt" for O-2 respectively. The rank of "LT" is a US Navy abbreviation for O-3.
Miranda says she was 16 years old when she gave birth to Kristin, so their age difference should be 16 years. Character ages are not specified in the film, but Julia Roberts is 23 years older than Britt Robertson, which is almost a 50% discrepancy. It's common for an actor's age not to match his/her character's age. Sometimes actors are younger that the actors playing their characters' children.
The family is in the RV, which is parked in the driveway. The sisters are seated on the couch, which is clearly in a slideout of the RV. The father drives off while they are still seated. That would not be possible with the slideout extended.
At the beginning of the movie, Sandy's son Mikey,
doesn't depress the inhaler when he uses it.
Sandy's sons attend the fictional Millard Fillmore Middle School. Atlanta, Georgia is not likely to name a school after a Yankee abolitionist president.
When Jason Sudekis (Bradley) is walking with the crutches, he is erroneously placing his weight on his injured foot when he should be placing his weight on his uninjured foot.