The most interesting part of “ The Mother,” a decent if forgettable action pic starring Jennifer Lopez, is the one that is left largely unexplored. The movie is a high-concept thriller that boils down to just a few words: She’s a mother and an assassin. OK, you’re probably thinking, fine.

Misha Green’s script was a hot commodity in 2017, around the time “Wonder Woman” opened, which had left some studios scrambling for action movies fronted by women. There were condescending headlines propping it up as a “female empowerment” script. And, eventually, with Niki Caro signed on to direct and a movie star like Lopez on board to star and produce, it was enough for greenlight and a Netflix budget. The final film also credits Peter Craig and Andrea Berloff for the script.

But history has unfortunately taught us to be suspect of a Mother’s Day rollout. The greeting card holiday is where studios always seem to dump mediocre material that happen to have women at the center. If the movies were better, you start to suspect, maybe they wouldn’t need the lame hook. Happy Mother’s Day! Here’s a woman doing... something!

This is a bit unfair to “The Mother,” which at worst is just what you expect it to be — a mostly generic action trifle that’s very self-serious and wants to be a lot of different kinds of films. Lopez’s character is basically Jason Bourne, James Bond, John Wick and Nikita rolled into one, at least when it comes to her skills which are vast and seemingly just the product of her tours in Afghanistan She’s. Just. That. Good.

After her military service, she’s left with few job prospects so she becomes a guard in Guantanamo and gets entangled, professionally and personally, with a few handsome arms dealers, Adrian (Joseph Fiennes) and Hector (Gael García Bernal). A bit of this is revealed in a brief prologue, in which she gives birth and has to give up the baby before even holding her. It’s for everyone’s safety and her only wish is that the kid gets placed with the most boring, stable family out there — that and that FBI Agent Cruise (Omari Hardwick) sends updates on her birthdays.

There is a “Mamma Mia”-esque mystery about who the father is and an even bigger mystery about if this pregnancy was planned or expected or wanted. And all of this is very interesting in theory. But the movie itself is set 12 years later when Mother learns that the daughter (who does get a name, Zoe) is in danger. This brings her out of her glamorously rugged Alaska retirement and back in action as a superhuman spy/assassin/one-woman army.

At first, Mother denies her Mother-hood to Zoe (Lucy Paez), whose foster parents get about as much character development and screen time as a couple in a cell phone commercial. This is supposed to be a big emotional journey for Mother and Zoe and the viewing audience, but I can’t say this movie ever really convinces you to care about this relationship, which is especially odd because there have been plenty of random pairings of adult assassins and non-blood relation children in movies that I’ve felt invested in. “The Mother” just expects that you’re on board with some essential connection, which Paul Raci (nice to see him again on screen) tries his best to sell.

As expected, Lopez is an athletic and capable action hero (maybe too capable, but that could also be said of most of the guys out there, too). This is taken much more seriously than the over-the-top “Shotgun Wedding” and Caro and her filmmaking team ably capture Lopez in all her glory, whether walking through the Alaskan snow framed by a fur hood, jumping out of multi-story parking garages and sliding over cars in a chase, or dancing with Fiennes in a body hugging dress. It’s all a much better showcase for Caro as a director in this big budget arena than the live-action “Mulan” was.

Lopez’s output has been prolific lately as she and her closest collaborators continue to look for interesting projects for her, undeterred by any Hollywood or societally imposed ideas about movies a woman in her 50s should be making. Romantic comedies, action movies – they’re all fair game, which is great. You just wish the movies could match the ambition.

“The Mother,” a Netflix release streaming Friday, is rated R by the Motion Picture Association for “violence, some language and brief drug use.” Running time: 115 minutes. Two stars out of four.