"Tully" reunites the "Juno" and "Young Adult" team of director Jason Reitman and Diablo Cody, in what feels very much like a spiritual heir to those movies, just advancing its surly, stressed-out protagonist from those awkward teen years to the exhaustion and depression associated with having a third child.Theron delivers a knockout performance as Marlo, who is not only struggling with the demands on her time but the added concern that comes from having a child with a behavioral issue. (They insist on referring to him as "quirky" and "out of the box," which doesn't make the tantrums any easier to handle.)Getting along with marginal help from her husband (Ron Livingston), Marlo receives an offer from her wealthy brother (Mark Duplass) to retain a night nanny, allowing her to get some rest. Resistant at first, she eventually relents, forging an unexpected bond with Tully ("Halt and Catch Fire's" Mackenzie Davis), a free-spirited 20-something who brings a bit of Mary Poppins-like wisdom into the household.Although the movie has an indie-film sensibility, there's something widely relatable about the pressures associated with parenting, as well as Marlo's hinted-at longings for the freedom she left behind, spurred by a chance encounter with an old friend. Notably, this is a movie without a bad guy, where the tension emanates from the real-feeling challenge of juggling more responsibility than one harried mom can bear alone."I'm here to take care of you," Tully tells her, a line whose seductive power is magnified by just how at her wits end Marlo feels.For those with an appetite for an early-summer movie with heart, but no costumes, "Tully" will take care of them, too.Alas, it's a long plunge from there to "Overboard," which flips the genders on a 1987 movie –starring Goldie Hawn and Kurt Russell — that had its issues then and certainly would have been even more problematic today.Anna Faris plays Kate, the widowed mom of three girls, who gets stiffed on a job by a Mexican billionaire playboy, Leonardo (Eugenio Derbez), after she's been hired to clean his luxury yacht. So when he falls into the ocean and turns up having completely lost his memory, she seizes on a hare-brained scheme to pretend that he's her husband, essentially turning him into an indentured servant for the month so she can focus on studying for her nursing test.Even for a jerk, convincing Leonardo that he has a family he doesn't remember until he has "paid his debt" seems cruel, making the notion that the two would gradually fall for each other harder to swallow. And while waiting for that to happen, all that's left, mostly, are a series of pratfalls, as the pampered heir — who has never worked a day in his life — tries to master a construction job and simple household chores.There is one clever reference snuck in to the original movie, but other than that, "Overboard" demonstrates that not every idea deserves an encore. If the gender switch fostered some curiosity, the result is a comedy that — even without amnesia — would better be forgotten."Tully" and "Overboard" open May 4 in the U.S. They're rated R and PG-13, respectively.