I don't think it's derogatory; it's just a type of parent. She's a middle-class mom, lives in the suburbs, who usually drives her children to sports practice (usually in a sports utility vehicle). So it's a actually someone who's actively involved in her children's interests and after-school activities.

It's basically a mother that has kids that play soccer. It kind of refers to a mother that has to take her kids to soccer practice a lot. It usually is not considered an offensive term.

I´m slightly surprised by the answers given by people from the US to this question, so I guess the interpretation of this term must depend on the situations in which one has heard this term being used. I am not from the US myself, however, based on the ways I have heard Americans use the term, I believe this term has taken on a more negative meaning lately (although it probably used to be a more neutral term when it was first "invented" back in the day). It may now (as far as I know) refer to being an overprotective parent / a mother who is over-regulating the free time of their children with too many after-school activities / a mother who is being perceived as "pushy" on behalf of her children. From the contexts within which I have heard this term used, I would say that today - in 2014, as opposed to earlier - this term is probably more often used to describe a stereotypical suburban mother (with negative connotations) than it is used to describe the neutral observation of dedicated mothers driving their kids to after-school activities. I would therefore avoid using it as an attempt to give someone a complement, if I were you :)

I would echo Christine's answer. It usually has a negative connotation. It's meant to sort of say, "This woman's life is so comfortable that the only important thing she has to do is take her kids to soccer practice." It's meant to jab at the privilege and comfort of a suburban, middle-class lifestyle that is insulated from a lot of the hardship other people face.

The wiki entry is consistent with my understanding, which is that "soccer mom" is sometimes used negatively today: "The phrase has taken on a negative aspect. Soccer moms are sometimes accused of forcing their children to go to too many after-school activities; overparenting them in concerted cultivation rather than letting them enjoy their childhood. In 2003, the car manufacturer Nissan, who had for several years courted the "soccer-mom" image, repositioned its Quest minivan as "stylish, sexy and desirable"." (http://en.wikipedia.org/wiki/Soccer_mom). This wiki entry also has an interesting explanation of the history and evolution of the term. Whether the term is used negatively or neutrally depends on the context, so I'd be careful how you use it.