Boruto’s power has been largely enhanced recently by his Karma mark and his Jougan. However, we know little about the Jougan just yet, as well as how it was awakened and it’s been hinted that Toneri may have assisted in Boruto’s Jougan awakening. Then, as for the Karma mark, we do know that this isn’t a natural ability and is a power passed onto Boruto through Momoshiki. However, in saying that, Boruto does have natural affiliations with Lightning, Wind and Water Nature Release, which is quite rare. In addition, Boruto’s genius in learning various Jutsu’s has been proven again and again.
As for Himuwari, we have seen that when she loses her temper, she can be quite dangerous. Himuwari without any training has been able to awaken the Byakugan and even use basic Gentle Fist attacks. Sadly, Himuwari is yet to receive any Ninja training and that means that she hasn’t been placed in a situation to develop those skills further or learn any more techniques. However, based on what we have seen thus far, Himuwari might even be naturally better at Ninutsu than what even Boruto is.
As a result, I believe that Himuwari has more Natural potential than Boruto. Most of Boruto’s strengths are derived from his experiences but as for Himuwari, hers thus far are all latent ability. However, that doesn’t mean that Himuwari will end up stronger than Boruto. The latter will continue to progress and work had to be an incredible Ninja, while as for Himuwari, she may still choose to not become a Ninja at all.