3. Kids will see people who have invisible illnesses.
Considered sickly all his life, Colin is portrayed as incredibly demanding at first. Mary first learns about Colin's existence after she hears him crying at night, and is keen on getting to know her cousin. During a later conversation, Mary questions why Colin never leaves his bed and whether or not he's really ill. Although there's a wheelchair close by, Colin explains that sometimes he "needs to be restrained or medicated" and that he's dying. While you can't tell Colin is necessarily sick by looking at him, it's a good reminder to kids that some illnesses don't manifest themselves outwardly.
4. There are scenes where a house burns down.
The scenes aren't necessarily violent or over-the-top scary, but the manor burns down toward the end of the movie. If you have a child who is uncomfortable by the sight of fire, feel free to fast forward through this part without losing much of the plot!
Image Source: STX Entertainment