It’s probably fair to say that Supergirl – likely to be the next costumed titan to get their own movie – is not the first DC superhero who springs to mind for the average comic-book fan. Batman, Superman and Wonder Woman occupy far taller plinths on the pantheon than Kara Zor-El, who, prior to the current TV series starring Melissa Benoist, was best known for the 1984 movie so terrible that the character’s fellow Kryptonians were probably happy to be dead and buried so they didn’t have to watch it.

Yet there is a problem with DC’s holy trinity. DC has ruined its plans for a shared universe centred around the three superheroes, with the heavy metal cacophony of Batman v Superman: Dawn of Justice having jarred horribly with the prosaic lilt of Justice League. If the studio, Warner Bros, has any plans to to get the gang back together again, it will have to do a much better job of getting audiences interested in its characters before trying to unite them in a money-spinning, Marvel-style mega-team.

The good news is that the best instalment so far has been Patty Jenkins’ Wonder Woman, which was cheerfully unconcerned with the rest of the DC extended universe (DCEU), the movie taking place in a different era to the other films. It also gave DC a refreshing boost in diversity, with Marvel having only recently caught up by offering ‎Evangeline Lilly the studio’s first female title role in Ant-Man and the Wasp. DC is now looking to go one step further by launching an entire cavalcade of female characters, from Batgirl to the mooted Birds of Prey movie starring Suicide Squad’s Margot Robbie as Harley Quinn.

A Supergirl movie therefore comes as little surprise, especially as the arrival of Kal-El’s older cousin on Earth was heavily prefaced in Man of Steel. Warner Bros needs to distract us while it fights to get itself out of this current mess. And what better than a standalone effort that has every chance of sticking it to the boys as impressively as Wonder Woman? The alternative might be to rely on the forthcoming Shazam!, which early trailers suggest will resemble an unholy blend of Chronicle and Big.

Facebook Twitter Pinterest Suicide Squad’s Margot Robbie is set to reappear as Harley Quinn in Birds of Prey. Photograph: Clay Enos/AP

One worry is that Batgirl and Supergirl end up upstaging Batman and Superman and rendering their male counterparts as obsolete as Zack Snyder’s power chord-heavy vision for the DCEU. But with uncertainty over when the caped crusader and Kal-El will next appear on the big screen – and who will play them – there is no harm in widening the DCEU.

Supergirl might even be a useful way to reintroduce Cavill’s man of steel into the DCEU – though we would have to hope that producers make a better job of such a cameo than their forebears. In the days before shared universes, the makers of the 1984 film tried and failed to convince Christopher Reeve to appear as Superman. A deal could not be reached, and a script had to be written explaining away Superman’s absence as a result of him having left on a peace-keeping mission to a distant galaxy. It never quite washed.

In the 80s, it was Supergirl who needed a favour from her more famous cousin. In 2018, the supershoe might well be on the other foot.

