Sigourney Weaver visited a Kmart and milked a goat in preparation for her role in "A Map of the World." That conscientiousness shows. The film overflows with the studied ordinariness that prevails in Mom movies, where glamorous Hollywood stars muck about in pajamas and a little epiphany may be signaled by a broken cereal bowl on the kitchen floor.

In this case, the calamity of a child's death is meant to shatter all the humdrum routine that once defined Alice Goodwin (Ms. Weaver) and her life on a Wisconsin farm.
...
One day, when Alice is watching her own daughters and baby-sitting the children of a close friend, Theresa Collins, she is too frazzled to notice that Theresa's younger daughter has wandered off. When the little girl drowns in the Goodwins' pond, their Wisconsin town turns into a latter-day Salem, and Alice must deal with the consequences.
--http://www.nytimes.com/library/film/120399map-film-review.html