Never work with kids or dogs, actors will tell you.

Marc Webb’s (“The Amazing Spider Man”) family comedy “Gifted” proves them right.

“Gifted” is of course about an Einstein’s size brain in the body of little Mary Adler (Mckenna Grace) who is 6 years old going on 38. Enrolled in school, she casually blows all the other kids away in math class, while still remaining a sweet, funny little girl.

Mary has lived with her Uncle Frank (Chris Evans, “Captain America”) for seven years. Frank a freelance boat repairman is not your average Bud drinking repairman. It seems that Frank used to be a college professor.

Uncle Frank wants his niece to grow up and be a normal little girl, so he puts her in a normal school with normal friends and a cute teacher, Bonnie, (a sweet Jenny Slate) who is impressed with her brain power.

On the school bus one morning, where the kids all have their paper mache projects, a bully destroys a shy kid’s project, and Mary busts junior Trump in the schnoz and breaks his nose. This is game changer.

Part 2: “When Frank Meets Bonnie.”

Both leads are cute and nice to look at, without being insufferably movie handsome — a welcome touch. We accept them.

Part 3: Mean Grandmother.

Coming home one day from school, Frank’s mama Evelyn (Lindsay Duncan) appears at Frank’s doorstep all dressed in Boston Beige with a British accent.

“Who is that?” Mary asks.

“That would be your grandmother,” Frank says, with a wince that would cut glass.

“Holy s..t” Mary says.

Part 4: Family Secrets.

We learn now that Grandma Evelyn, a British expat, was once a Harvard math genius herself and, we learn that her daughter, Frank’s sister, was a world class math genius who, had she lived, might have been the new Archimedes.

SPOILER ALERT: She didn’t, she committed suicide after Mary’s birth, and now after 10 minutes with Evelyn, we suspect we know why.

Grandma has come to rescue little Mary from this sordid middle-class swamp, get her in the best schools, and make her what her daughter could have been. Can you see where this is going?

By now Frank and Bonnie are a couple, and within five minutes of falling in love. But Grandma isn’t giving up.

She hires a lawyer and we find ourselves in court. Frank’s lawyer proves that his client is a model citizen, and the judge agrees.

Part 5: Frank has no Obamacare.

That’s right, no insurance, and that being the deal breaker, we soon move into tears, screaming, separation anxiety and gloom.

But, If Frank will agree to put Mary in a nearby private school with other geniuses, Grandma will drop the case.

But when Frank discovers that the school is kind of a Betsy DeVos master race factory for the gifted, he pulls her out.

Sorry to say that this script is not a nail biter by any means. You’ll be happy with the outcome, you’ve seen it coming for 101 minutes.

Mark Webb is only interested in tugging your heart strings, not pulling them out by the roots.

Chris Evans is surprisingly good and uncomplicated. Jenny Slate as teacher Bonnie is sweet and uncomplicated,

Octavia Spencer, who can’t get another good role in White Hollywood despite an Oscar, is tossed in as Frank’s lovable, tough and uncomplicated landlady.

Lindsay Duncan as Grandma Cruella de Vil is very complicated, and just when we thought we had a nice, uncomplicated family comedy that wouldn’t upset the Freedom Caucus, Grandma opens up at the end with …

Part 6: Dark family secret.

So actors have been proven right; Little Mckenna Grace is terrific, and wipes the adults off the screen. There’s no dog, but wait for it.

Part 7: Mary has a heartbreaking one-eyed cat that is threatened with euthanisia. Take that.

J.P. Devine is a former movie and screen actor.