Prove it. She fought him as a (mostly) complete equal.
They clashed and her thunder bagua lost to his iirc
She was in hybrid form when she performed most of her feats towards Kaidou, but when she slammed Aramaki she was in base form using a nameless attack. Oda him self has said and proven that zoans get much stronger in hybrid and full forms. This is true for any transformation in one piece, basically. I have an essay explaining this: -Zoan transformations increase strength, instinct, etc. And full transformations make them achieve their peak strength, speed, durability, etc. This is by extension the same with most transformations in One Piece as seen with people like Enel and Big Mom.
-We see this when Yamato transforms and slams Hybrid ( hybrid but not fully transformed ) Kaidou and iirc makes him cough blood, completely serious in this context and is trying their all to hold off Kaidou until Luffy arrives.
-Yamato, in base form, uses an unnamed attack against a fully transformed, completely serious Admiral. Admiral falls to the ground, praises the hit, and grits their teeth. Should be noted that said Admiral isn't bleeding since plants, to my knowledge, do not bleed. Yamato seemingly is not completely serious in this battle and has reliable back up this time, thus saying she was using a full power attack or an attack on par with her transformed attacks is simply wanking due to the logic and proof Oda previously provided showing a transformed zoan's attack is far superior and more dangerous than a base attack. Also shown when Kaidou was only able to slightly injure Luffy with a Thunder Bagua during the final rounds of their battle before the gear 5th awakening, but a transformed Kaidou used an updated Thunder Bagua and shut down Luffy's heart, forcing luffy to awaken to live from it. Basically, Yamato's feats against Kaidou are far better and nigh uncomparable to the unnamed base attack she did to Aramaki.