"Waitress" has a tragic behind-the-scenes backstory. Writer-director-star Adrienne Shelly, 40, was murdered in her New York City apartment last November, only a little over two months before her film was to premiere at the Sundance Film Festival. Shelly, predominantly working within the indie world, was a great acting talent, and "Waitress" was to be her highest-profile picture as a filmmaker, to date. She may not be around to reap the accolades the movie has so far received, but it will forever mark her as a thriving artist just as gifted behind the camera as she was in front of it.

"Waitress" is not a perfect film, nor is it a groundbreaking one, but there is an unabashed warmth and sweetness about it that cannot be denied. A humor-laced slice-of-life with undercurrents of both sadness and whimsy, the movie feels a bit like "The Good Girl"-lite, as a working-class gal in small-town America comes to a crucial crossroads in her life just as she discovers she is pregnant. Desperate to run away and praying that happiness may someday find her, she dreams about breaking free from her unhappy marriage just as she falls into a guilty affair with another man. "The Good Girl," which starred Jennifer Aniston in the best role of her career, was the stronger of the two—deeper, darker, and more touching—but they both share one other common characteristic: a brilliant performance from their respective leading lady.

In "Waitress," Keri Russell (2005's "The Upside of Anger") gives a revelatory turn as Jenna, a young woman with a knack for creating and baking pies. Toiling away at a sleepy cafe called Joe's Pie Shop when she isn't suffering through a smothering marriage with her emotionally and physically abusive husband Earl (Keri Russell), Jenna is thrown another unforeseen corkscrew when she finds out she's with child. Jenna is not happy about the thought of becoming a mother, but she is adamant about having the baby—preferably with Earl out of the picture. This is easier said than done, though, and before long she has given in to her desires with new town obstetrician Dr. Pomatter (Nathan Fillion).

Writer-director Adrienne Shelly brings a lighthearted but deft touch to "Waitress." As an indie dramedy, the film is hardly original or all that surprising. Most of the story developments can be seen coming a mile away, and the way in which Shelly wraps everything up seems a little too pat and convenient, bordering on something one might expect from a fairy tale. Still, Jenna's undesirable and undeserved lot in life is captured with a sure and empathetic hand. She's a kind and generous human being without being written as a saint, and is prone to making mistakes, as we all do. One clever quirk in Shelly's pleasantly written script is the way in which Jenna envisions each life situation she encounters as a different pie, and there are some hearty laughs from the ingredients she chooses to fit each mood.

Not since her days in the title role of TV's "Felicity" has Keri Russell received a part with such emotional range and so many layers. She is a pure delight as Jenna—funny, likable, and occasionally downbeat as she flounders in an unhealthy marriage she does not know how to get out of. Russell handles every scene with a blinding honesty that makes Jenna feel more authentic and real than the average screen protagonist. As Dr. Pomatter, Nathan Fillion (2006's "Slither") has a tougher job in that his role is less defined. Fillion is amiable as the man most likely to make Jenna happy, but the viewer never gets a sense of why he is so drawn to her when he has a perfectly wonderful wife (Darby Stanchfield) at home. Jenna has an excuse for their romantic entanglement—Earl is a needy, insecure and violent lunkhead—but what little of Dr. Pomatter's life is discussed lacks an understanding of the actions he himself makes.

The supporting cast is bright and memorable. Cheryl Hines (2006's "RV") is joyfully brassy and Adrienne Shelly is adorable and intentionally meek as Jenna's fellow waitress buddies Becky and Dawn. Lew Temple (2005's "The Devil's Rejects") gets some good moments as manager Cal that humanize him beyond the conventions of the character. Andy Griffith makes a welcome return to the screen as the restaurant's ornery owner Old Joe, whom Jenna forges a subtle and endearing unlikely friendship with. Rounding out the ensemble are Jeremy Sisto (2003's "May"), spiteful and pitiful in his possessive nature as Jenna's hubby Earl, and Eddie Jemison (2004's "The Punisher"), winning as Dawn's sincere, nebbish boyfriend Ogie.

The general premise of "Waitress" perhaps would be better suited for the small screen, whether it be as a sitcom a 'la 1970s series "Alice" or a one-hour comedic drama like the current "Men in Trees." To be sure, things do not often veer from the oft-trodden path of its narrative, and it is the sharp character work that is most noteworthy. Nevertheless, watching the film is a genial and appealing experience, and Keri Russell essays a heroine that is worth rooting for and caring about. No matter the lowly circumstances Jenna is confronted by, the viewer actively hopes that she will find the contentment in life that has always floated just outside her grasp.

• The Adrienne Shelly Foundation