This movie is not at all for the younger set. It is a movie about real life and, although there's nothing wrong with that, most younger kids don't need to be exposed to those things quite yet. There are hard lessons in this movie....coming to grips with a life that didn't turn out the way you wanted it to, the difficulties in raising children, and the emotional aspects of living with a pet who becomes a member of your family. There were a lot of positive things here.....a husband and wife who truly seem to be in a loving relationship where they both do things to help make the other one happy, showing the realities of being frustrated with a pet and yet still loving and caring for it as part of the family, and children who really seem to get along as siblings.
The sexual aspects of the film are not explicit, and they could open a conversation with older children about where babies come from, etc., but it is not something that children younger than 8 or 9 need to even have an inkling of, I think.
Overall, this is not a "for the whole family" type of movie. If anything, it is a movie that is best enjoyed by adults, although there would be little worry for teenagers watching it. It is, however, very highly emotional and could really upset more sensitive children and youths.