Rose Byrne (left) and Mark Wahlberg appear in a scene from “Instant Family.”

Being a parent is hard enough, but being a foster parent is really challenging,

That is the basic premise for “Instant Family,” a film about family that, for the most part, mixes the delicate balance between laughs and pulling at the heartstrings. With Mark Wahlberg and Rose Byrne’s comedic chemistry leading the way, “Family” finds its stride early and avoids any major stumbles – making it a nice option for families this holiday season.

Wahlberg and Byrne play Pete and Ellie, a fairly successful couple who have made a nice living out of renovating houses and flipping them for profit. It’s a lifestyle that hasn’t included children, a choice the couple seem content with until Ellie’s sister and brother in-law reveal their plans to start a family.

Ellie and Pete decide to adopt and connect with a 14-year-old named Lizzy (Isabela Moner) during a local adoption fair. The couple decided they want to be Lizzy’s foster parents, but it comes with a catch – Lizzy’s siblings Juan (Gustavo Quiroz) and Lita (Julianna Gamiz).

At first, it seems to be a perfect fit, but Ellie and Pete soon start to think they’ve taken on more than they can handle as problems arise – making them reassess their desire to be foster parents.

“Instant Family” seems to have a good grasp on the adoption process, and really conveys the highs and lows of both the foster parents and the children who are sometimes shuffled from home to home.

Sean Anders (who also directed) and John Morris’ screenplay walks a tightrope where the film could have easily veered into trying too hard to be funny and being overly sentimental, but manages to keep that pitfall in check for the most part. Perhaps it helps that Anders has already explored the shifting family dynamics in a pair of “Daddy’s Home” movies – films that are far inferior to this one, perhaps showing Anders has learned from his mistakes. “Family” sometimes feels like it is about to drift into cornball territory, only to have a moment so genuine and real it gets back on track.

“Family” also benefits from its cast – starting with Wahlberg and Byrne. They are perfectly believable as this couple – with the pair having great comedic chemistry throughout. The kids are also good, especially Moner, while there is some good supporting work from Octavia Spencer and Tig Notaro as foster parent counselors and Margo Martindale and Julie Hagerty as Pete and Ellie’s mothers – both eager to be grandmothers.

“Family” isn’t a perfect movie, and a cameo by Joan Cusack feels forced, but its messiness fits its subject matter. It’s a film that finds humor in tough situations, leaving audiences laughing and reaching for the tissues quite often.

Starring: Mark Wahlberg, Rose Byrne

Directed by: Sean Anders

Rating: PG-13 for thematic elements, sexual material, language and some drug references

Playing at: Regal Bowling Green Stadium 12, Regal Greenwood Mall Stadium 10, Highland Cinemas (Glasgow)

Grade: B-