The main thing that separates women's fiction from either romance or "general" fiction, is that it focuses on relationships. Now, obviously, this will include romance, but the relationship in question does not always have to be romantically inclined.
Spouse or significant other
Mother/daughter or Father/daughter
Brother/sister or Sister/sister, including twins and half-siblings
Grandparents, or other extended family, or step-family
Friends (obviously) of any gender or age
Familial relationships are by far the most common, because 1) there are many different options to choose from and/or mix and match, and 2) pretty much anyone can relate to family issues (even people who have no family, because that, in itself, is a family issue). Anything with universal appeal is going to do well.
This is where you have your "divorce/ affair/ widow" stories. And your baby clause stories (or anything regarding parenting). And your "I can never forgive my mother/ sister/ whoever because they [fill in the blank]" stories. And pretty much anything else you can think of that would affect the MC and a member of his/her family as the main plot. Sibling stories can be somewhat compared to friendship stories, but there is more depth to it than that.
These stories offer the most variety in type. There is no "typical plot", really, but many of them trend toward drama with a bit of occasional comedic relief. "Parenting" and "significant other" stories have the most opportunity to actually be sub-categorized as comedy.
A few examples:
What's Eating Gilbert Grape?
Sins of the Mother
Cheaper by the Dozen
Mr. and Mrs. Smith (really? yes, really. sub-category action/suspense, but it's a relationship story at heart. see what I mean about variety with this type?)
Workplace stories in women's fiction often fall under the sub-genre of humor/comedy, and this is also where a lot of chick lit is found (because younger women are supposedly more career-focused rather than family-focused). There is sometimes romance involved, but not necessarily anything regarding family members. And many times these become friendship stories as well because the co-workers have to find a way to work together toward a common goal.
The Devil Wears Prada
Nine to Five
Friendship stories are often intertwined with family stories and, sometimes, romance. But the focus of the plot is always the relationship between friends. It is thrown into the proverbial fire, and the climax is the point when the MC decides to either 1) ditch the bad friend(s) and move on, or 2) embrace them despite the flaws they can't seem to fix. It is usually the latter, but not always.
The best friendship stories are a good balance between drama and comedy. Here are just two examples:
Now and Then
What are some of your favorite relationship stories?