When Caroline is giving Ben his bath, she drops both the soap and sponge into the bathtub water. When she comes back to the bathtub, the soap is still floating in the water, but the sponge has appeared on the rack over the tub.
When Caroline is reporting for her interview, she steps out of her car and walks up to the house for the first time. We see her back from the car's side mirror. In reality, the car is parked (and she walked) in a direction that would not allow her to be visible in the car's side mirror.
Toward the beginning of the movie, Caroline takes a shower and goes to sleep. She is awoken by Ben crawling on the roof and goes outside to save him. The rain makes her faces drip mascara, which she never had time to put on since her shower.
When Caroline is showing Jill the newspaper ad for the hospice job, she has circled it numerous times with wide pen strokes. When Jill looks at it again, the pen strokes have obviously changed positions, more an oval shape.
When Caroline makes a 911 call, she gives the street address of the house and says it's "in Terrebone Parish." Parishes are like counties in that they are composed of many, many different small towns and cities. She would have to give a specific city/town name in order for emergency vehicles to get there. However, because the house isn't located in any particular town (but rather out in the swampland), it is more likely that the address given to 911 by Caroline IS the full address, and that what is supposed to be a street name is actually just a name of a very scarcely settled small town with no particular streets. Thus, an address consisting of just a town name and house number would be legitimate.
At the end of the movie Caroline is brought into the house by Luke. She has her hands tied behind her back and has mascara streaking down her face. When we see her again, the streaks are not running down her face but just around her eyes, yet she has no hands free to wipe them off.