At the opening, 40-year-old Mary Jo Walker (Janet McTeer) is being assaulted once again by her nasty-tempered husband. He's her fourth hubby (she has problems saying, "no," to marriage proposals), but she also is not the kind of woman who will allow being mistreated. Soon after, she and her preadolescent daughter Ava (Kimberly J. Brown) have hit the road, like they always do when Mary Jo has man troubles, headed in no particular direction. They have never seen the beach, so they end up moving to San Diego, CA, where Mary Jo gets a job as an office secretary and Ava becomes fast friends at school with fellow classmates Zoe (Ashley Buccille) and Adam (Cody McMains). After a chance meeting with Jack Ranson (Gavin O'Connor), a truck driver who previously had helped fix their car, Mary Jo, once again, believes that Jack is "the" one, and before long, Mary Jo and Ava have moved in with him. Ava clearly doesn't like Jack; she can see right through his thin facade, and fears that if the relationship between her mother and him grows rocky, she will find herself uprooted to another town somewhere else.

As a mother-daughter tale, "Tumbleweeds" is meticulous and believable. The relationship between Mary Jo and Ava is so very unaffected because the screenplay, by O'Connor and Angela Shelton, knows exactly what goes on between a close parent and child. The dialogue exchanges between the two are also right on the money, as is the casting of the two central roles.

Janet McTeer, an English stage actress, is exceptional, not only pulling off a southern accent with nary a flaw in sight, but also transforming Mary Jo into a strong-willed woman whose best friend is her daughter, and gives her all the love and care a child should have. That isn't to say Mary Jo is perfect; she grows scared and dispirited if she doesn't have a husband or boyfriend at all times, and, inevitably, also seems to pick the wrong men. Mary Jo fools herself into believing a man stands for security and can fill up the missing hole in her personal character, but all it really does is cause her constant hardships. When things don't seem to be going well, Mary Jo simply packs up (and sometimes even leaves her belongings) and sets off for another town, never looking back.

Kimberly J. Brown, as Ava, has the more difficult role because she is the one who acts as the voice of reason for her mother. Ava is dedicated and loyal to Mary Jo, rarely ever complaining about her severely dysfunctional life of settling down and moving out, but she is also growing into a teenager, and realizes that running away isn't the answer for everything. Brown, a newcomer to feature films, is not at all a child actor who mugs in front of the camera, or attempts to steal a scene away from others. She doesn't need to, because she often does this without even trying. Brown compliments Ava as a girl on the edge of her teenage years, still in the learning process of boyfriends and kissing. Ava can sometimes act spoiled or bratty, but that only comes with the territory of being a child, and otherwise, is a likable character who we can't help but follow with a close eye through the story.

Lending fine support are two impressive supporting turns by Laurel Holloman, as Mary Jo's friend and coworker Laurie, and Jay O. Sanders, as Dan Miller, a kind widower who may be the perfect match for Mary Jo, if only she could see it. In the subplot involving Dan, the turnout isn't exactly as expected, but seems nothing if not truthful to the characters.

When Jack Ranson, played by writer-director Gavin O'Connor, enters the picture as Mary Jo's new blossoming boyfriend, the film instantly becomes more conventional and predictable. We, as the audience, know that Jack isn't quite as charming as he may appear to be at first glance, and it is inescapable that bliss will only last so long, and Mary Jo will want to get out of San Diego as quickly as possible. There then will be a confrontation where Ava will attempt to get her mother to understand they don't have to run away any longer, that she is her own person and her life shouldn't have to revolve around that of men.

The way "Tumbleweeds" ends is understated and, looking back, very little is solved. Without giving anything away, it is unavoidable to wonder whether Mary Jo really will follow through with her new path in life or not, and Ava's blossoming sexuality is cause for concern. Ava may be the one that sees the mistakes her mother makes, but you have to question whether she might end up just like her when she gets a little older. "Tumbleweeds" is a delicate drama, short on plot but rich in memorable characters. It may have its fair share of shortcomings, but the stunning work by McTeer and Brown is cause for celebration, all by itself.